How to Get Pregnant With Irregular Periods

Irregular Cycle Causes + Natural Ways to Conceive + Fertility Treatment Options

Woman looking at a calendar to predict her period. When you have irregular periods, it may be difficult to get pregnant.
If you don't know when your period is coming, it may be harder to know when you're ovulating.. Vstock LLC / Getty Images

Can you get pregnant with irregular periods? Yes. Irregular periods can make getting pregnant more difficult. But they don't necessarily mean you won't be able to get pregnant on your own.

How easily you'll be able to conceive depends on a number of factors, including:

  • the cause of your irregular periods
  • how irregular your periods are
  • whether or not you can time sex for pregnancy accurately 

Some women with irregular cycles will need to use fertility treatments.

Sometimes, making lifestyle changes can regulate previously irregular periods and help you conceive.

We'll discuss all these options below. 

Are Your Cycles Irregular?

An irregular period is defined as a menstrual cycle that is either shorter than 21 days, or longer than 36 days.

Your cycle may also be considered irregular if they vary significantly from month to month.

For example, if one month your cycle is 23 days, and another it's 35, and then another it's 30, you might say you have irregular cycles.

An occasional irregular cycle is normal. Stress or illness can cause a delay in ovulation or menstruation, causing your cycle to be longer, and sometimes shorter, than usual.

So, if you have just one or two "off" periods a year, don't worry. 

However, if your cycles are often irregular, or you go quite a long time between menstrual cycles, you should see your doctor for an evaluation.

What Causes of Irregular Cycles Make It Harder to Conceive?

As mentioned above, the cause behind irregular cycles has a lot to do with your chances of getting pregnant.

Sometimes, irregular periods are a sign of anovulation. Anovulatory cycles are menstrual cycles where ovulation doesn't take place.

If you're not ovulating, you can't get pregnant.

Irregular periods may be a sign of polycystic ovarian syndrome (PCOS). Depending on whether you ovulate on your own or not, you may be able to get pregnant by yourself with PCOS.

A common cause of irregular periods and decreased fertility is obesity. Being overweight (or underweight) can disrupt your menstrual cycles and make it harder to get pregnant.

Extreme exercise and extreme dieting are also potential causes of irregular cycles. Female athletes are more likely to experience infertility for this reason.

Sometimes, irregular cycles point to a more subtle hormonal imbalance. You may still be ovulating month to month. Just that your ovulation day varies greatly.

If you're ovulating, you may be able to get pregnant without the help of fertility drugs.

Catching the Egg When Your Cycles Are Irregular

If you are ovulating, but irregularly, you'll need to make a special effort at detecting your most fertile time.

There are many ways to predict ovulation. You might need to use more than one to help figure out when is the best time for you to have sex.

An ovulation predictor test may be able to help you time sex for pregnancy. These tests work a lot like pregnancy tests, in that you pee on test strips to determine when you're most fertile.

However, in some women, the tests give multiple "false positives." This is especially common in women with PCOS.

You may want to consider charting your basal body temperature (BBT). BBT charting can show you when you actually ovulated.

Plus, you can share your BBT charts with your doctor. She may be able to use this information to make a diagnosis.

You may also decide to forgo trying to detect ovulation and just have sex frequently throughout your cycle. 

There are many benefits to taking this approach.

For one, some couples find timing sex for pregnancy stressful. This avoids that stress. You won't be trying to have sex when you get the positive ovulation test result or whatever. You'll just have sex... frequently... all month long!

Secondly, you don't have to worry about missing ovulation. If you're having sex three to four times a week, you'll probably have sex on a fertile day.

What Else Can You Do to Get Pregnant With Irregular Cycles?

If it turns out that you are not ovulating, you may need fertility drugs to help boost your ovulation.

Clomid is the most commonly prescribed drug for ovulatory dysfunction, and it has a high success rate.

Another possible option is the drug letrozole. This cancer drug is used off-label to trigger ovulation.

Research has found it to be possibly more effective than Clomid in women with PCOS.

If these medications don't work, your doctor may suggest moving onto injectable fertility drugs (gonadotropins), IUI treatment, or even IVF. 

Fertility drugs aren't your only option.

You may be able to make lifestyle changes.

If you are overweight, losing some of the weight may be enough to jumpstart ovulation and help you conceive. And you may not have to lose all of the weight.

Research has shown that obese women who lose just 10% of their weight can start ovulating on their own again.

If extreme dieting is the problem, changing your diet to a more balanced plan, and even gaining some weight if you're underweight, can help regulate your cycles.

When to Talk to Your Doctor About Irregular Cycles

If you have irregular periods, the best thing to do is see your gynecologist.

Even if you weren't trying to get pregnant, it's a good idea to get checked out.

Usually, the recommendation is that you try to get pregnant for one year (or six months if you're age 35 of older), and then, if you don't conceive, to see a doctor. 

However, this doesn't apply if there are signs of a problem.

Irregular cycles is a risk factor for infertility. Your doctor can run some simple blood tests to see if you are ovulating or not.

If your blood work indicates that you are ovulating, and you're not over 35, you might want to keep trying to get pregnant on your own for a bit longer.

Ovulation problems are a common cause of female factor infertility, with a pretty good treatment success rate.

There's no shame in needing some help. Don't be afraid to seek it out.

More on getting pregnant:


Abnormal Uterine Bleeding. American College of Obstetricians and Gynecology Education Pamphlet. Accessed September 29, 2008.

Menstruation. American College of Obstetricians and Gynecology Education Pamphlet. Accessed September 29, 2008.

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