What is irregular period?

Having irregular periods can mean a variation in the number of days you have your period or that your period arrives early, late or even skips a few months.

Actually, most women will experience irregular bleeding at some point in their life. A period showing up unexpected or delayed does not always mean something serious is going on. But your period showing up whenever it wants can be stressful. So here we’re going to talk about some easy ways of how you can regulate your menstrual cycle.


4 common causes for irregular periods:

The average length of a Menstrual Cycle is around 28 – 35 days, and menstrual bleeding usually lasts between 3 – 7 days. Keep in mind that what is a normal or average period for one person, can be experienced completely different by another. So if your period suddenly varies from your average length and flow, it’s a sign that your period is irregular.

Your period may show up earlier than expected, or not show up at all. Here are the 4 most common causes that can cause a delayed or early period thus causing an irregular menstrual cycle:

  1. – Medication
  2. – Stress and anxiety
  3. – Puberty or menopause
  4. – Hormonal birth control such as contraceptive pills or emergency contraception

Irregular Periods – What do they mean?

Often irregular or early periods don’t mean anything serious. However, if you realize a sudden change in your menstrual cycle, it could be a symptom for another health issue such as:

  • Thyroid Disorder (over- or underactive thyroids can cause a hormonal imbalance which can suppress your ovulation)
  • Diabetes
  • STD (Sexually Transmitted Disease)
  • Pregnancy (Irregular periods can sometimes be a sign of pregnancy. If you think you could be pregnant, see your doctor for a consult.)
  • Polycystic Ovary Syndrome (PCOS)

PCOS affects 5-10% of women, but less than 50% with the syndrome are diagnosed. This is why it’s really important to see your doctor if you suspect that your irregular menstrual cycle could be linked to another issue.

What is Polycystic Ovary Syndrome (PCOS)?

Apart from an irregular menstruation other symptoms of PCOS are:

  • Acne
  • Excess hair growth on face and body
  • High blood pressure
  • Depression and anxiety

If you have PCOS, your hormones are out of balance and there are small cysts on and in your ovaries. If you think you have PCOS, schedule an appointment with your doctor or general practitioner.

Why is my period late? Possible reasons for a missed period

Your menstrual cycle is controlled by hormones, which, if imbalanced, can cause irregularities to your menstrual cycle and period flow. The most common cause is a fluctuation in your hormones (especially when it affects your estrogen levels):

  1. – Stress, travelling and a hectic lifestyle can release stress hormones, which can disrupt the production of estrogen and cause a late or missed period.
  2. – Your diet and unhealthy eating can impact your body and your flow. Similarly, sudden weight gain or loss, as well as malnourishment, can cause an irregular menstruation.
  3. – Medication and contraception; hormonal birth control methods such as the pill or the injection can affect your period.
  4. – Puberty, Menarche and Menopause, are phases in your life where high hormonal fluctuation is normal.
  5. – Excessive exercising can often cause periods to be delayed or not come at all.

When to see a doctor

Irregular periods are common. But you might just want to check in with your gynaecologist and tell them you’re having irregular periods. They can do a quick safety check to make sure the cause for your irregular periods is nothing to be worried about.

If you find that irregular periods are taking over or making your day-to-day life difficult, then visit your doctor for a health check. Many find that their periods are more irregular during puberty or menopause. A missed period can also be an indication of pregnancy, so if you are unsure, see your doctor.

If your periods suddenly change, you should also go see a doctor. Maybe it’s because of stress, but better to rule out any other causes for sure.

3 easy ways to regulate your period naturally

Regulate your period by adjusting your diet

It’s important you have a balanced and healthy diet all month. There are some particular foods that are very helpful in regulating periods and getting your menstrual flow going:

Pineapples and papaya are well-known home remedies for irregular periods. The bromelain in the pineapple and papaya will help soften and break down your uterus lining, which can help solve a period block.

Also, aim for an intake of half a teaspoon of cinnamon (mixed in warm lemon water with honey or in a glass of (almond) milk). Some studies show that cinnamon helps regulate the insulin levels, which in turn can help regulate ovulation and therefore also having a regular menstrual cycle.

Destress & Self-care

Stress is one of the most common reasons for irregular periods. So naturally, a cure for irregular periods is to break out of your stressful, daily routines – even if only for a couple of hours.

Try taking a hot bath or place a hot water bottle or a warm cherry stone pillow on your abdomen and do a relaxing activity. Read a book or magazine, listen to a podcast or watch your favourite show.

If you can, try meditating or keeping a gratitude journal. It’s about taking some me-time and zoning out of your usual day to day thoughts and routine. Turn off your laptop, turn off your phone and try to relax and take care of yourself (even if it’s just half an hour.) If you have long office hours or study all day long, even taking 5 or 10 minutes perhaps outside or somewhere away from your desk can help you relax and clear your mind.

Regular exercise

Anything from yoga to CrossFit – as long as you feel comfortable, exercise is also a great stress release. You can also just go for a walk or do some easy youtube workouts at home. The important thing is to do some kind of exercise that takes your mind off things and helps you break out of your daily chores and routines. Just a little bit can give you that small kick of endorphins you need to destress.

Tips to make irregular periods easier to manage:

Track your period, improve your life

Tracking your period will help avoid unwanted period surprises. You will be able to calculate when your next period most likely will be due and easily adjust your plans towards potential cramp and PMS days.

In order to know when you’re period is becoming irregular, you must first know your flow. By keeping track of your period, you can calculate when to expect your next period. After about 3 cycles you will begin to see a pattern and know how your average menstrual cycle behaves. You will also be able to detect abnormalities faster and have data to show to your gynaecologist.

There are some great apps available that can help you track your period easily.

Find a menstrual product that feels right for you

You never know exactly when your period is going to start, so whenever you feel today might be the day, you precautiously protect your underwear with some internal or external period product.
But stress, insomnia or medication can delay a period for a couple of days, and taking out a dry tampon or having to throw away another unstained pad is very uncomfortable and frustrating. That’s why menstrual cups (read this if you don’t know what a menstrual cup is) are a great solution for being prepared for when your period actually does show up: no drying out, you can leave it in for 12 hours and you don’t waste any disposable menstrual products.

There are a bunch of other reasons why menstrual cups make managing irregular periods easy:

  • You won’t run out of period products or be caught off-guard because they are reusable
  • Cups are made from a healthy material, so they don’t dry you out or leave any cotton residue behind
  • If your period is heavy, they are a good solution due to their higher capacity (3x a super tampon)

Hopefully, you found all the information about irregular periods that you were looking for. Check out Laci Green’s video about irregular periods for a deeper understanding.

We also hope you found the tips on how to regulate your menstrual cycle naturally useful. Remember, each body works differently and it’s important that you find out what works best for you. There are many ways on how to manage irregular periods. Maybe switching to a menstrual cup makes handling your irreagular period easier, or you find it helpful to adjust your diet – or a combination of both. In any case, if you still have some questions, don’t hesitate to ask in the comments and consult with your doctor.

(Medical Disclaimer: We are not medical doctors, therefore, we cannot give medical advice. This information is for educational purposes only.)

Are Irregular Periods Normal? 9 Causes of Abnormal Menstruation That Are More Common Than You’d Think

We’re raised to expect our menstrual cycles to run for exactly 28 days, on the dot — so when our periods are irregular, some of us are inclined to totally freak out. Could this irregularity be caused by some rare kind of disease that we’ve never even heard of? And if we’ve recently engaged in any boner-based sexual activities, a late period can often leave us mere moments away from acting out the opening scene in Juno.

Conversely, a consistently irregular period can also leave us with worries about our own fertility. Does an irregular period mean your ovaries aren’t working properly? Could you have trouble conceiving, if you decide to have a baby later on? Will you never get the chance to act out the opening scene in Juno??

About 30 percent of women experience irregular periods (sometimes also referred to as “abnormal menstruation”) — which means a menstrual cycle that varies in length from month to month — at some point during their reproductively fertile years. And while sometimes irregular periods can be a sign of a serious health problem, more often, there’s nothing all that abnormal about them — they can be a byproduct of stress, certain lifestyle habits, or even just a function of age.

So how can you tell a worrisome irregular period from a totally regular irregular period? It’s obviously always a good idea to check with a gyno or other doctor whom you trust and who takes your opinion seriously when your body starts behaving in an unexpected way. But before you make your appointment, read on to learn a little bit more about the various causes of irregular periods.


Causes: Unprotected heterosexual intercourse; accidentally sitting in a big bucket of fresh sperm.

If your irregular period is caused by being pregnant, you’re probably going to find that out pretty damn quickly. But pregnancy is one of the most common causes of a late or irregular period — especially because some women continue to have light, irregular periods early on into their pregnancy. So if your irregular period began right after you raw-dogged Steve from Accounting after a particularly wild Margarita Monday, go get yourself checked out.

Going Off the Pill

Causes: You recently stopped taking the pill.

It’s kind of ironic, since many women with irregular menstrual cycles are put on the pill to regulate them — but if you’ve just stopped taking birth control pills, it can take as long as six months for your body’s normal menstrual cycles to return. So if you’ve just stopped popping your pills and can’t seem to properly schedule your visits with Aunt Flo (or her daughter, Cousin Bloodyunderpants), don’t panic.

Polycystic Ovary Syndrome

Causes: Genetics; excess insulin; low-grade inflammation (usually in response to an infection)

If you’ve had irregular periods for a while, many doctors will automatically assume that you have PCOS, a very common endocrine disorder (it’s estimated that 5 million American women have PCOS). Though it sounds scary — it can lead to excessive body hair growth, acne, and infertility — PCOS can be helped with a variety of treatments, including the pill and diabetes medications.

But if you’re genuinely concerned that you have PCOS, ask your doctor for a full PCOS diagnosis exam, which may include blood tests and vaginal ultrasounds. Many OB/GYNs dismiss any period irregularity as PCOS, which can lead to over-medication for those who don’t actually have a problem, or failing to get treatment for the real cause of your irregular periods, so a test might be a good idea.

Primary Ovarian Insufficiency

Causes: In most cases, the cause of POI is unclear; but sometimes, the disorder is the result of a genetic or chromosomal problem, or an autoimmune disease.

Primary Ovarian Insufficiency is a serious health problem that disrupts hormone production, and effects one in 100 women under the age of 40. Sometimes incorrectly referred to as “premature menopause,” POI causes your body to inconsistently produce hormones, which reveals itself in irregular periods. But the irregular periods aren’t the real problem — POI can lead to bone density loss and trouble conceiving down the road, so it’s important to get it treated.

But POI has a lot of other symptoms, too — like hot flashes, vaginal dryness, pain during sex, and sudden onset of irregular periods after a history of consistent periods — so don’t assume that you have it just because you’re irregular. And with early treatment, women with POI can still conceive and bear children — in fact, 5 to 10 percent of women with POI are still able to conceive naturally, without any medical treatment at all.

Being A Teenager

Causes: Having been born more than 10 but less than 20 years ago.

It can take several years for your periods to settle into regular cycles after you start getting them. I can tell you this because science says so, and also because I got my period at 11, and didn’t have regular periods until some time in high school. Prior to that, I’d go up to six months at a time between periods (since I was not sexually active at the time, I was often hopeful that this meant that God had finally listened to my prayers and taken away my annoying-ass period). Many good pairs of panties and stonewashed Gap jeans lost their lives in the Gabrielle Moss Irregular Period Wars of 1993-5. So if you’re relatively new to Periodsville, don’t get hung up on the irregularities.

Being Stressed Out

Causes: School; work; other human beings; sometimes, just the mere prospect of waking up and going through another day of trying to figure out what any of this all MEANS, man.

Stress is considered the most common cause of irregular periods — when you’re stressed, your body floods with cortisol, which can interfere with the hormones that regulate your period. Luckily, there is an easy solution for this one — cut ties with everyone you know and start a new life selling turquoise jewelry in Taos, New Mexico. Or, also, you could try stress relief methods like yoga, exercise, or meditation. Whatever, your call.

Taking Mood-Regulating Drugs

Causes: Certain anti-anxiety, anti-depressant, and anti-psychotic drugs.

Certain drugs designed to lessen depression or anxiety can end up causing a ton of new anxiety by giving you irregular periods. If your irregular periods began right after you started a new medication, talk to your psychiatrist — it may be a common side effect of your new pill that no one bothered to warn you about.

Losing or Gaining Weight Very Quickly

Causes: Losing or gaining a lot of weight, in a very short period of time.

Though there are a ton of reasons for sudden weight gain or loss — thyroid disorders, illnesses, eating disorders, intense athletic regimens — a common thread among them is that sudden changes to your weight can lead to sudden changes in your cycle, including irregular periods or not getting your period at all. The good news is that your periods will generally return to normal once you body returns to its healthy weight. But if you’re not sure why you’ve suddenly gained or lost a lot of weight, please go check in with a doctor (if you do know why you’ve suddenly lost a lot of weight and it involves potentially dangerous behavior, please go check in with a doctor, too).


Causes: Pumping milk out of your boobs — possibly into a baby’s mouth, possibly somewhere else… frankly, it is none of my business.

The hormone fluctuations we experience when breastfeeding can sometimes cause irregular periods, or even a total lack of period. Your cycles will probably return back to normal after you wean your kid, but some women experience permanent changes to their cycles post-childbirth, too. And the only known cure is to participate in one of the breastfeed-ins at the mall — okay, I lied. There is no treatment, I just think breastfeed-ins are really cool. Fight the power (with your boobs)!

And remember: no matter what, your irregularity still makes you a totally regular woman.


Images: Disney; Giphy (10)

Top things to know:

  • A normal period length for someone who’s not using hormonal birth control or an IUD is 8 days or less
  • Hormonal birth control methods like the pill, patch, ring, or IUD often make period lengths shorter
  • Copper IUDs may make period lengths longer

The length of your menstrual period is the number of continuous days of bleeding within each of your menstrual cycles.

Your menstrual period is the shedding of your endometrium (the lining of the uterus). During your period, blood and endometrial tissue flow down through your cervix and vagina. The first day of your period is considered the first day of your menstrual cycle.

Periods are a healthy and normal part of the menstrual cycle. But prolonged or heavy periods are associated with iron deficiency, which can lead to anemia and/or feeling unwell (1-3). Long or heavy periods may also be one sign of a health condition that should be addressed with a healthcare provider. It is possible to have heavy menstrual bleeding even when your period length is within range.

Short periods are generally less of a concern, but may be an indication of a health condition in some cases. A sudden, short period may also sometimes be spotting from a pregnancy (4).

Spotting or bleeding on days that are not continuous with the menstrual period should not be considered part of the period, and should be noted in your period tracking app as spotting.

If your period is irregular or prolonged, speak to your healthcare provider. It could be due to many underlying health conditions, such as polycystic ovarian syndrome, fibroids, uterine polyps, or bleeding disorders (3,5).

What is the normal period length for people not on hormonal birth control?

Adult period length

For an adult who is not using any form of hormonal birth control or IUD, a normal period length is up to 8 days (6).

The first two days of the period are usually the heaviest flow, with the latter days having progressively less blood (7). Variations between differing period length and cycle lengths are normal, as your period changes over your reproductive life (7,8). If your period length is regularly longer than eight days, consult your healthcare provider (6,7).

Adolescent period length

The period length of adolescents around the time of menarche, the first menstrual period, can vary greatly. It’s common for cycles to be somewhat irregular for a few years after your first period. This means your periods may not always come at the same time every cycle, and they may be somewhat different cycle-to-cycle. As you progress through adolescence, period lengths and cycles become more regular, but may still be somewhat variable (9,10).

A normal period length for an adolescent usually ranges between 2 to 7 days, but may sometimes be longer or shorter (9).

What is the normal “period” length for people on hormonal birth control (e.g. the pill, the ring, the patch)?

Hormonal birth control (HBC) options like the pill, vaginal ring, or patch control the release and regulation of hormones like estrogen and progesterone within your body. When used correctly, the hormones in your HBC prevent your ovaries from preparing and releasing eggs (ovulation).

Your number of bleeding days and cycle length will depend on the type of HBC you use. Bleeding typically happens during your “no hormone” days (when you take placebo pills, or the times in between new rings or patches). The bleeding you experience while using hormonal birth control is called withdrawal bleeding, and is not considered a menstrual period. Withdrawal bleeding is caused by the decline in reproductive hormones in your body during days when you get low or no hormones from your pill, patch, or ring (6,11).

Many people experience lighter bleeding and some don’t bleed at all while using hormonal birth control (12). When affected by hormonal birth control, the lining of your uterus doesn’t thicken as much as it does without hormonal birth control. This typically results in lighter, shorter, or occasionally absent “periods,” especially for people who have been using hormonal birth control for many months or years.

Some people also decide to skip any bleeding while using HBC, by skipping over the “no-hormone” days. Some hormonal birth control options have a cycle that mimics a normal cycle length (usually 28 days), while other types of hormonal birth control are continuous, which limits bleeding to once every three months, or even once a year (11).

What is the normal “period” length for people on progestin-only birth control (e.g. the mini pill, the shot, the implant)?

There are many different types of hormonal birth control, all containing differing types and levels of hormones. Some types of birth control do not contain any estrogens and only contain progestins—a synthetic form of progesterone (13). These methods include progestin-only pills (the mini pill), progestin injections (the shot), or progestin implants (13).

Bleeding can vary a lot on progestin-only contraceptives. Changes in period length and heaviness happen in response to the changes in hormones. These hormones affect the growing and shedding of your uterine lining.

Methods like the contraceptive injection and the implant usually suppress ovulation (14,15). Some progestin-only pills also suppress ovulation, but it depends on the type (13). Most people who don’t ovulate due to progestin-only contraceptives experience shorter, lighter, or occasionally absent bleedings days, though this doesn’t always happen (13).

Unpredictable bleeding, spotting, and prolonged bleeding are common when using these methods, especially during the first few months (16). These symptoms usually improve with time, but they can continue for some people.

What’s the normal period length for people with intrauterine devices (IUDs)?

Your period on the hormonal IUD

While using the hormonal IUD, it’s common to experience irregular bleeding or lighter bleeding, and some people don’t bleed at all (8,13,18). This happens because the endometrium doesn’t thicken as much as it does when you’re not using hormonal birth control. This typically results in lighter or occasionally absent bleeding, especially for people who have been using the hormonal IUD for many months or years (13).

Your period on the copper IUD

Many people experience heavier and longer bleeding while using the copper IUD, especially in the first 6–12 months (13,19). This may happen due to vascular changes and changes to blood flow in the uterus (18,20-22). Bleeding may be accompanied by an increase in large clots and cramping. Using nonsteroidal anti-inflammatory drugs (NSAIDs) may help reduce bleeding and pain (13).

Copper IUDs are non-hormonal, so you will experience the same fluctuations of estrogen and progesterone across your cycle as you did when you weren’t using a copper IUD.

Prolonged or irregular bleeding on birth control

Starting a new method of birth control can cause changes the amount of days you bleed. Irregular bleeding is common when starting a new birth control method and usually goes away within three months.

Be mindful of how your bleeding days change and how you feel on an new form of birth control. Different brands and types of hormonal birth control contain different levels of reproductive hormones, so some brands or types may be better suited for you than others. Talk to your healthcare provider about trying another brand if you have continued spotting three months after starting a new method, or if your bleeding has gotten heavier (3).

Prolonged bleeding on hormonal birth control can also be caused by underlying health conditions such as uterine fibroids or an untreated infection (3,23).

If you suspect that your period is prolonged or irregular, speak to your healthcare professional. When talking to your healthcare provider, show them your tracking history. Also tell them if you’ve recently noticed unexpected changes in your body, such as unexplained abdominal pain, difficulty controlling your weight, or unusual hair growth on your face or body. This can help them identify what might be causing your long periods (13).

Why periods vary

The length of your typical period is determined by your age, genes, health, body mass index (BMI), behaviors, and birth control methods (23).

If you’ve had your period for a few years, it should generally be about the same length and volume each cycle. You may still notice changes from time to time— the heaviness and length of your period depends on your hormones, which can fluctuate due to factors like diet, stress, or taking an emergency contraception pill (the morning-after pill) (1,25-27).

Periods can fluctuate in cycles where ovulation doesn’t occur. This is why periods can fluctuate during adolescence, after giving birth, during breastfeeding, and during perimenopause (the menopausal transition) (28,10). People are less likely to ovulate consistently during these times.

Exercise, smoking cigarettes, and drinking alcohol may also affect period length and heaviness (29-34).

to track your menstrual period.

Irregular Periods

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What Are Irregular Periods?

Even though girls get their periods on a cycle, that cycle can take different amounts of time each month. For example, a girl might get her period after 24 days one month and after 42 days the next. These are called irregular periods.

Irregular periods are very common, especially in a girl’s first few years of getting her period.

What Are Regular Periods?

Most girls get their first period between the ages of 10 and 15, but some get it earlier and some later. The first period is known as menarche (pronounced: MEN-ar-kee).

A girl’s monthly cycle is the number of days from the start of her period to the start of the next time she gets her period. You often hear this is a 28-day cycle. But 28 is just an average figure that doctors use. Cycle lengths vary — some are 24 days, some are 34 days. And a girl may notice that her cycles are different lengths each month — especially for the few years after she first starts getting her period.

Early in a girl’s cycle, her ovaries start preparing one egg. At the same time, the lining of the uterus becomes thick to prepare a nesting place for a fertilized egg in the event that the girl becomes pregnant.

About 2 weeks before a girl gets her period, the egg is released from the ovary (this is called ovulation). The egg travels through the fallopian tube into the uterus. If the egg isn’t fertilized by sperm, it starts to fall apart. Then the lining and egg leave a girl’s body as her period and the whole thing starts all over again — that’s why we use the word “cycle.” The first day a girl’s period comes is Day 1 of her cycle.

A girl’s body may not follow an exact schedule. It’s common, especially in the first 2 years after a girl starts getting her period, to skip periods or to have irregular periods. Illness, rapid weight change, or stress can also make things more unpredictable. That’s because the part of the brain that regulates periods is influenced by events like these. Going on a trip or having a major change in schedule can also make your period come at a different time than expected. All of this is perfectly normal.

It’s also normal for the number of days a girl has her period to vary. Sometimes a girl may bleed for 2 days, sometimes it may last a week. That’s because the level of hormones the body makes can be different from one cycle to the next, and this affects the amount and length of bleeding.

If My Period Is Irregular, How Do I Know When I Will Get It?

If your cycle is not regular, you’ll want to pay attention to the clues your body may give you that your period is coming soon. These may include:

  • back cramps or stiffness
  • heavier breasts or breast soreness
  • headaches
  • acne breakouts
  • disturbed sleep patterns
  • mood swings
  • bloating
  • loose stools

How Can I Be Prepared?

Keep some pads or tampons in your backpack or purse, just so you’ll have them handy in case your period comes when you’re not expecting it. You may even want to carry an extra pair of underwear.

What Causes Irregular Periods?

Most of the time, irregular periods are part of the normal changes that can happen when you’re a teen. As you get older, your cycle will probably settle into a recognizable pattern.

Sometimes, irregular periods can be caused by some medicines, exercising too much, having a very low or high body weight, or not eating enough calories.

Hormone imbalances can also cause irregular periods. For example, thyroid hormone levels that are too low or too high can cause problems with periods. Some girls have extra androgen, a hormone that can cause hair growth on the face, chin, chest, and abdomen. Extra androgen can also makes girls gain weight and have irregular periods.

Girls who are pregnant also will not get their periods.

Should I Worry About Irregular Periods?

Talk to your doctor if you have had sex and have missed a period because you could be pregnant. Also let the doctor know if:

  • You were having regular periods that then become irregular.
  • You stop getting your period.
  • You have extra hair growth on the face, chin, chest, or abdomen.
  • You start having periods that last longer than 7 days, are heavy, or are coming more often than every 21 days.
  • Your period comes less often than every 45 days.
  • You have severe cramping or abdominal pain.
  • You have bleeding in between your periods.
  • Your periods are irregular for 3 years or more.

The doctor may prescribe hormone pills or other medicines, or recommend lifestyle changes that can help you to have regular periods.

Reviewed by: Robyn R. Miller, MD Date reviewed: December 2018

5 Things You Need to Know About Irregular Periods

You thought you had it all figured out, but then everything changes. We’re talking about your period, of course, which has a knack for lulling you into a false sense of predictability and then suddenly flipping the script.

Thought your period came at the end of the month? Now it’s at the beginning. Not to mention the entire month your period skipped.

It turns out irregular periods are pretty common — even for people on birth control. Here’s what you need to know about what’s normal and what’s not.

Irregular is different for everyone

“The most important thing for patients to understand is your period and your regularity is different from other people’s,” says Dr. Ying Zhang, a family medicine doctor who sees patients at the UW Neighborhood Northgate Clinic and the Family Medicine Clinic at Harborview Medical Center.

Maybe you’ve heard that a ‘normal’ cycle is between 28 and 30 days. Or that your period should last four or five days max.

This may be true for some people, but in reality periods can vary a lot more and still be considered normal.

Cycles that last as few as 21 days or as long as 40 days are possible, Zhang says.

In terms of length, a normal period usually lasts between two and seven days.

So if you occasionally skip a period or your period comes late some months, there’s probably nothing to be worried about. Still, if you’re thrown off by your period’s irregularity and want to get a better sense for any patterns … well, there’s an app for that.

“A lot of people use period tracking apps, which is helpful to understand what is happening with their cycle and the duration,” Zhang says.

Many things can cause irregular periods

You know that stress you’ve been feeling about your new job or moving into a new house? It can wreak havoc on the regularity of your cycle.

During times of your life that are more stressful, your period could be more irregular, Zhang says. This could mean it comes later or even skips a month.

Other things that can cause irregular periods include weight gain or loss; medical conditions like a thyroid disorder or ovulatory dysfunction; high levels of testosterone, such as what happens to women who have polycystic ovary syndrome; or putting a lot of stress on your body due to a strict exercise regime, which sometimes happens to female athletes.

And, for those who are wondering, infertility can cause irregular periods — but not the other way around, Zhang says. If you’re experiencing fertility issues and aren’t menstruating regularly, there’s probably an underlying medical issue that you need to address, so make sure to talk with your doctor.

Your period can change over time

Maybe you used to get a heavy flow during your periods, but now they’re lighter. Or maybe some periods are lighter and others are a little heavier. This is pretty normal, Zhang says.

“It depends on what’s going on with the lining in your uterus,” she says.

The time between each cycle can also vary: Maybe one month it’s 28 days, then the next it’s 30 days.

Your PMS symptoms (or lack thereof) can vary each cycle, too, depending on hormone fluctuations, Zhang says.

It’s not uncommon for your period to become shorter as you get older, too. In adolescence, periods tend to be longer and a little heavier, then ease up after a few years. Menstruation changes in the years before menopause and can be more irregular after pregnancy.

Birth control can make your period irregular — at first

Hormonal contraceptives like birth control pills and the hormonal intrauterine device (IUD) work to prevent pregnancy by interfering with the natural fluctuation of hormones in your cycle that form eggs and ovarian follicles. This interference is what prevents you from getting pregnant.

Some hormonal contraceptives, like the hormonal IUD, also prevent pregnancy by thinning the lining of your uterus, known as the endometrium, so an egg can’t attach to it.

A thin endometrium means your body doesn’t need to shed it as often or at all, so your period may become much lighter or stop altogether, Zhang says.

Spotting or bleeding between periods can happen when you start using a new method of hormonal birth control, Zhang says. Plus, some people choose to use birth control in a way that suppresses their period entirely, like taking birth control pills continuously (and skipping the placebo pills), which can also result in spotting until your body gets used to the new routine.

But if you have spotting or bleeding between periods that doesn’t go away within a few months, or if there’s a sudden change in your cycle, that’s worth noting, Zhang says.

“If you’re on an IUD and you don’t get your period, if all of a sudden you have heavy bleeding or have irregular bleeding, that is something to ask your doctor about,” she says.

Some symptoms are more concerning than others

While a skipped period isn’t automatically cause for concern, a few other things can be.

If you suddenly start getting a heavy flow during periods or start bleeding between periods (and you haven’t recently started a new type of hormonal birth control), that’s something you’ll want to bring up to your doctor, Zhang says.

Likewise, if your cycle lasts less than 21 days or more than 40, it’s also worth a visit to your primary care provider. If you skip more than three periods in a row and aren’t pregnant, that’s also something you’ll want to get checked out.

Getting severe cramps during your period, when you previously didn’t, could also be cause for concern.

The bottom line: If you think something’s up, even if it’s supposedly normal, just get it checked out. For example, Zhang sees many patients who come in because of a skipped period, which is something they’re concerned about but that isn’t necessarily a red flag to a doctor.

“If you’re having new symptoms that are concerning to you, it’s always fine to go talk with your doctor about it,” Zhang says.

Summit Medical Group Web Site

How long does a normal menstrual cycle last?

A menstrual cycle is the time from the day a menstrual period starts to the time the next period starts. The average menstrual cycle is 28 days long. However, a normal cycle can be shorter or longer than this. It may be anywhere from 21 to 35 days long. Most periods last 3 to 5 days, but anywhere from 2 to 7 days is normal. Menstrual cycles may happen around the same date every month or they may be irregular.

When is a period late?

A menstrual period is considered late if it hasn’t started 5 or more days after the day you expected it to start. A period is considered missed if you have had no menstrual flow for 6 or more weeks after the start of your last period.

What is the cause?

During the first couple of years of menstruation many teenagers have irregular periods. During this time your body is still developing and the ovaries may not release an egg every month. As a result, your cycles may be irregular, occurring as close together as 2 weeks or as far apart as 3 months. If you have been having periods for 2 years or less and your physical exam is normal, your irregular periods may be part of your normal development.

Most girls’ menstrual cycles become fairly regular as their hormone levels mature and synchronize. A few women will continue to have irregular cycles as their normal pattern.

Other causes of a late or missed period are:

  • Pregnancy
  • Stress
  • Hormone imbalance


Pregnancy is the most common cause of missed periods in teenage girls. If your period is late and you have had sex even once in the past several months, see your healthcare provider. It’s best to see your healthcare provider for a pregnancy test because home test kits can be confusing and give incorrect or unclear results.

It is important to find out early if you are pregnant. Starting prenatal care right away helps you have a healthy baby.

If you are pregnant, you will not have a normal period until after the baby is born.


Stress is the second most common cause of late or missed periods in teenagers. It may be emotional stress (for example, breakup with a boyfriend or final exams) or depression. Or it may be physical stress to the body, such as a severe illness, a sexually transmitted disease, rapid weight loss or gain, or strenuous exercise. Dieting or binging and purging may interrupt menstrual cycles. Changes in your usual routine (for example, going on vacation) may also cause your period to be late or missed.

Some stress is a normal part of daily life. Too much stress for your body may cause a late or missed period. Your periods should come back when you change your activities or situation.

Hormone imbalance

In some cases hormone imbalance is causes missed periods. For example, if you have been taking birth control pills, your periods may be irregular for a while when you stop taking the pills. If you are having sex, be sure to use another reliable method of birth control because you could still get pregnant.

A rare problem called polycystic ovary syndrome can affect a young woman’s menstrual cycle. Polycystic ovaries may cause irregular cycles, more body hair, acne, and weight gain. It can be treated with hormone medicine prescribed by your healthcare provider.

Problems of the thyroid gland, pituitary gland, adrenal glands, or ovaries are other rare causes of irregular periods.

How can I take care of myself?

  • Mark on a calendar the dates when each period starts and stops. This information can help your healthcare provider make a correct diagnosis. Take the calendar to your appointment.
  • Eat healthy foods and keep your weight steady.
    • If you are overweight, a balanced diet and regular exercise will help you lose weight slowly. It’s best to lose no more than 2 pounds a week.
    • If you are underweight, make sure you are getting enough nutrition.

    Talk with your healthcare provider if you are not sure what your proper weight should be, or if others are worried about your weight. A nutritionist may also be able to give you helpful advice.

  • If you follow a strenuous exercise program, consider cutting back until your periods come back. If you don’t want to cut back on your exercise, see your healthcare provider to see if you need to cut back on exercise, eat more calories, or need treatment.
  • If you have sex, always use birth control. Talk to your healthcare provider about your choices.
  • If you have had sex, get a pregnancy test if your period is 5 or more days late. Don’t wait. You can get confidential testing and counseling in most healthcare providers’ offices and clinics.
  • See if you can get some counseling if you are feeling stressed out.

7 Reasons for a Late Period That Don’t Mean You’re Pregnant

Other types of hormonal birth control like intrauterine devices (IUDs) and the Depo-Provera shot can also cause late and irregular periods. Dr. Patounakis cautions that no contraceptive is 100 percent effective at preventing pregnancy. So if you don’t get your period three or four days after starting the inactive portion of the pill pack, for example, you should take a pregnancy test.

2. Polycystic Ovary Syndrome (PCOS)

During a typical menstrual cycle, each ovary develops roughly five follicles, and those follicles compete to become the dominant one that will release a mature egg at ovulation. Women with PCOS often have additional follicles, which makes this process take longer than usual. No released egg means no period.

Other PCOS symptoms include weight gain and increased levels of the testosterone-like hormone androgen, which can cause thick hair growth on the face and breasts. But even without these symptoms, one can’t rule out PCOS. “There are women who are not overweight and don’t have extra hair who have irregular cycles and an ultrasound will show they have excessive follicles,” says Anuja Vyas, M.D., FACOG, with Houston Methodist Obstetrics and Gynecology Associates.

Image zoom Marcos Mesa Sam Wordley/

3. Stress

How stress affects the menstrual cycle is highly subjective because what’s considered stressful depends on the woman, says Dr. McDonald. Moving across the country or dealing with a challenging work situation could throw off one woman’s cycle by a week or even cause it to arrive early, but have no effect on another woman.

Stress can interfere with the hypothalamus, causing a trickle-down effect. “Emotional distress can affect the region of the brain that controls the pituitary gland, which regulates the hormones that stimulate our ovaries,” explains Dr. Vyas.

4. Fluctuating Weight

Excessive weight loss is more likely to cause a late period than weight gain, though increasing body weight, when related to other conditions like PCOS, can have a similar effect. “A body mass index (BMI) under 20 creates a starvation-ish mode in the brain,” says Dr. McDonald. “That’s why some really lean female athletes don’t have periods—being underweight creates an environment that’s anti-pregnancy.”

“Severe weight loss and anorexia can shut down the hypothalamus’s production of follicle stimulating hormone (FSH) and luteinizing hormone (LH) that regulate the ovaries,” adds Dr. Vyas.

PCOS patients may be especially sensitive to the numbers on the scale. “As little as 10 percent weight loss can get them back into their cycle after experiencing irregularity,” explains Dr. McDonald. “And a similar percentage of weight gain can cause a late or missed period.”

5. Perimenopause

“The average age women in the U.S. experience menopause is 51, but many women start having delayed menstrual cycles in their late 40s,” says Dr. Vyas. So instead of the standard 28 days between periods, menses may arrive 36 or 48 days apart. “If you’re under 45 and your period stops completely, it’s possible you’re going through early menopause or experiencing premature ovarian failure,” she adds.

  • RELATED: 8 Facts About Your Cycle and Conception

6. A Pituitary Tumor

Though it’s rare and unlikely, sometimes a prolactinoma, a type of pituitary tumor that secretes excess amounts of prolactin, the hormone that signals breast milk production, is to blame for a late period. Dr. Vyas says women who are suffering from headaches, blurry vision, and discharge from the breasts even though they’re not breastfeeding, in addition to a menstrual cycle that’s off, may want to get checked by their doctor for this type of tumor.

7. Diabetes and Thyroid Disease

Jay M. Berman, M.D., FACOG, chief of gynecological services at Detroit Medical Center’s Harper Hutzel Hospital and professor of obstetrics and gynecology at Wayne State University, says other issues such as diabetes and thyroid disease can be associated with late or absent menstrual cycles. “Many women will, for various reasons, occasionally not ovulate and this can cause an early or delayed menses,” he says. “Depending on her history, it may require further testing to determine the cause.”

Lastly, it’s important to note that vaginal bleeding after a late period may not be the monthly visitor you were expecting. “Anybody who experiences heavy bleeding and pain after a missed period and/or a positive pregnancy test should go to the doctor,” says Dr. McDonald. “All bleeding is not a period, especially in a setting where is something is off.”

  • By Maria Carter

Menstrual Period – Missed or Late

Is this your child’s symptom?

  • Late or missed menstrual period
  • Late period: 5 or more days late compared to normal menstrual cycle
  • Missed period: no menstrual flow for more than 6 weeks
  • Teen not using any birth control that stops periods. These products include birth control shots, implants, and IUDs with hormones.

Normal Cause of a Missed Period during the First Year

  • Skipping periods is common during the first 1 to 2 years after they start. This is due to not releasing an egg each month.
  • This is most likely the cause if less than 2 years since the first period
  • Has missed periods in the past or has had only 1 or 2 periods
  • Otherwise healthy
  • No signs of pregnancy such as breast tenderness, breast swelling or nausea

Common Cause of a Missed Period after the First Year

  • Pregnancy is the most common cause

Other Causes

  • Stress
  • Dieting, extreme exercise and weight loss
  • Polycystic ovarian disease
  • Endocrine disorders
  • Birth control products like birth control shots, implants, and some IUDs

Home Urine Pregnancy Tests

  • Home urine pregnancy tests do not cost very much. They are easy to use. Most drugstores sell these tests. No prescription is needed.
  • Urine pregnancy tests are very accurate. They can turn positive as early as the first week after a missed period.
  • It is best to do the pregnancy test first thing in the morning. Reason: hormone levels are higher in the morning urine.
  • Sometimes, a home test is negative even if you think you might be pregnant. In this case, repeat the test. Do the repeat test in 3-5 days. You can also go to a doctor’s office for testing.
  • A pregnancy testing fact sheet can be found at www.womenshealth.gov. Search “pregnancy tests.”

When to Call for Menstrual Period – Missed or Late

Call Doctor or Seek Care Now

  • Your teen looks or acts very sick
  • You think your teen needs to be seen, and the problem is urgent

Call Doctor During Office Hours

  • Home pregnancy test is positive
  • You want a pregnancy test done in the office
  • Sexual intercourse (had sex) within the last 3 months
  • Recent breast swelling, weight gain or nausea
  • Teen acts sick
  • Has missed 2 or more periods and prior periods were regular
  • Recent weight loss
  • Excessive exercise suspected as cause of no periods
  • First period started less than 1 year ago and has missed 4 or more periods
  • Age 15 or older and periods have not started
  • Cause is unknown (not recent onset of menstrual periods or recent stress)
  • You think your teen needs to be seen, but the problem is not urgent
  • You have other questions or concerns

Self Care at Home

  • Pregnancy suspected or possible
  • First period started less than 1 year ago and has missed 3 periods or less
  • Recent stress (such as starting at a new school, break-up) causing late period

Seattle Children’s Urgent Care Locations

If your child’s illness or injury is life-threatening, call 911.

Care Advice

Pregnancy Suspected or Possible

  1. What You Should Know About Late Periods if Having Sex:
    • Menstrual periods stop when a woman becomes pregnant.
    • A woman with a missed or late period should think about pregnancy.
    • Here is some care advice that should help.
  2. Pregnancy Test, When in Doubt:
    • If there is a chance that you might be pregnant, use a urine pregnancy test.
    • You can buy a pregnancy test at any drugstore.
    • It works best first thing in the morning.
    • Follow all package instructions.
  3. Call Your Doctor If:
    • You have trouble with the home pregnancy test
    • Pregnancy test is positive
    • Misses 2 periods and pregnancy test is negative
    • Your teen develops any serious symptoms

First Period Started Less than 1 Year Ago

  1. What You Should Know About First Periods in Young Teens:
    • Skipping periods is common during the first 1 or 2 years after they start.
    • It doesn’t mean anything serious or cause any harm.
    • A girl can normally go up to 6 months between the first and second periods.
    • Also, a girl can go up to 4 months between the second and third periods.
    • Normal irregular periods can go on for 2 years.
  2. Call Your Doctor If:
    • Misses 4 periods
    • New symptoms suggest pregnancy (such as morning sickness)
    • You have other questions

Recent Stress Causing Late Period

  1. What You Should Know about Stress and Late Menstrual Periods:
    • Stress can disrupt normal menstrual cycles.
    • Try to help your daughter deal with the stress by talking about it.
    • Also, try to avoid or decrease stressors.
    • If this does not help, seek help from a counselor.
  2. Call Your Doctor If:
    • Misses 2 periods
    • Your daughter needs help coping with stress
    • New symptoms suggest pregnancy (such as morning sickness)
    • You have other questions

And remember, contact your doctor if your child develops any of the ‘Call Your Doctor’ symptoms.

Disclaimer: this health information is for educational purposes only. You, the reader, assume full responsibility for how you choose to use it.

Last Reviewed: 02/01/2020

Last Revised: 03/14/2019

Copyright 2000-2019 Schmitt Pediatric Guidelines LLC.

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