Irregular periods can be annoying and inconvenient, but happily, they're usually nothing to worry about. Still, because irregular menstrual cycles can occasionally signal an underlying hormonal imbalance or can sometimes make conceiving a baby slightly more difficult, you should discuss any irregularities in your cycle with your doctor during your checkups. 

Your doctor can diagnose your condition and prescribe the right treatment to help get your periods — and your fertility — back on track.

What are irregular periods?

If you have irregular periods, your actual period may seem normal — the amount you bleed and the number of days you bleed are similar to a typical period — but they happen at unusual intervals (more than 45 days or fewer than 21 days apart), at unpredictable intervals or a combination of these.[1]

What causes irregular periods?

Occasional irregularities in your menstrual cycle are most commonly due to stress, travel, excessive exercise or another temporary change to your normal routine.

Cycles that are consistently irregular are more often due to factors such as an eating disorder, weight loss or weight gain, thyroid levels that are too high or too low, or hormonal imbalances (including those related to starting, stopping or missing doses of birth control pills, patches or other prescribed estrogen supplements).[2]

The most common cause of chronically irregular periods is a disorder called polycystic ovary syndrome (PCOS). And, of course, a missed or abnormal period could also be due to pregnancy.

Missed or irregular periods can also be a sign of compromised ovarian function.

How can you tell if you have irregular periods?

Tracking your menstrual cycles (by noting the first day of your period on your calendar or period app over the course of a few months) will help you learn if your cycles are actually irregular or just a bit shorter (or longer) than the typical 28 to 30 days average cycle. Keeping track can also help your doctor better determine whether treatment is necessary.

Can you get pregnant if you have irregular periods?

Yes. Irregular menstrual cycles don’t always affect fertility. In fact, plenty of women with irregular menstrual cycles get pregnant and go on to have normal pregnancies. So if you're wondering whether irregular periods mean infertility, the answer is no, but this may make it harder for you to get pregnant.

When your periods are irregular, it makes it more difficult to know when to try to conceive. Usually women will track their cycles to determine when ovulation happens.

But going months without bleeding and then getting your period without any discernible pattern, or always having irregular periods, can make that type of tracking unreliable. Instead you’ll have to be on the lookout for other signs of ovulation, since cycle length won’t tell you when to time baby-making sex.

The real concern when it comes to irregular periods is that occasionally the condition might indicate irregular or absent ovulation. And if you don’t ovulate, you can’t get pregnant. Problems with ovulation are responsible for up to 30 percent of all cases of infertility. 

If an ovulation problem is a possibility, now's the time to consult an evaluation with your physician to see if you will need help getting pregnant or if there are any underlying health issues that should be addressed first.

How are irregular periods treated?

If irregular periods are chronic, bothering you or making it difficult for you to conceive, speak to your doctor to find out if there’s a way to get them back on track. That can involve trying to lower your stress levels (extreme stress can derail your cycles) or cutting back on intense exercising (which could also prevent you from ovulating and having regular periods).

Your doctor can also perform an evaluation to assess hormone levels and possibly do an ultrasound examination. There are a variety of treatments available based on the diagnosis that your physician makes and your goals to conceive (or not). For example, he or she may suggest and may include treating an underlying thyroid condition or using therapies to regulate your menstrual cycle. 

If you are trying to get pregnant and have irregular cycles, your physician will perform an evaluation and may recommend  a fertility drug like letrozole (Femara), clomiphene (Clomid) or injectable fertility meds to induce ovulation, but you should have a complete fertility evaluation before starting any of these drugs.

Rest assured that if you have irregular periods, it doesn't mean you won't be able to have a healthy pregnancy and baby. However, even if you are not trying to get pregnant, it is important for you to consult with your physician to make sure that nothing is being missed and that you can understand what the best options are for you.