If your period is irregular can you still get pregnant

Irregular periods aren't always a sign of a problem, but sometimes it's a good idea to see a doctor about them just in case.

What are irregular periods?

You have irregular periods if the length of your menstrual cycle (the gap between your periods starting) keeps changing.

Your periods may come early or late.

The average menstrual cycle lasts 28 days, although it's normal for it to be a bit shorter or longer than this.

After puberty, many women develop a regular cycle with a similar length of time between periods. But it's not uncommon for it to vary by a few days each time.

Causes of irregular periods

There are many possible causes of irregular periods. Sometimes they may just be normal for you.

Common causes include:

  • puberty – your periods might be irregular for the first year or two
  • the start of the menopause (usually between the ages of 45 and 55)
  • early pregnancy – take a pregnancy test to rule this out
  • some types of hormonal contraception – such as the contraceptive pill or intrauterine system (IUS)
  • extreme weight loss or weight gain, excessive exercise or stress
  • medical conditions – such as polycystic ovary syndrome (PCOS) or a problem with your thyroid

When to see a GP

You don't need to get medical advice if you have always had slightly irregular periods or you're still going through puberty.

But see a GP if:

  • your periods suddenly become irregular and you're under 45
  • you have periods more often than every 21 days or less often than every 35 days
  • your periods last longer than 7 days
  • there's a big difference (at least 20 days) between your shortest and longest menstrual cycle
  • you have irregular periods and you're struggling to get pregnant

There might not be anything wrong, but it's a good idea to get checked out to see what the cause might be.

You might be referred to a specialist called a gynaecologist if you need any tests or treatment.

Trying for a baby

It can be more difficult to get pregnant if you have irregular periods because you might not ovulate (release an egg) regularly.

It can help to have sex every 2 or 3 days throughout your cycle. You don't need to time sex around ovulation.

Read more about trying to get pregnant.

Sometimes hormone medicine or fertility treatment may be needed if you're struggling to get pregnant naturally.

More about periods and other period problems

Read more about:

  • periods and the menstrual cycle
  • heavy periods
  • stopped or missed periods
  • period pain

Video: menstrual cycle

This animation explains in detail how the menstrual cycle works.

Media last reviewed: 21 October 2020
Media review due: 21 October 2023

Page last reviewed: 27 April 2021
Next review due: 27 April 2024

When your periods are irregular, trying to conceive (TTC) can be challenging.  Women with regular periods are four times more likely to conceive than women with irregular periods.  Fortunately, that doesn’t mean that natural conception isn’t possible and many women with irregular cycles go on to have healthy pregnancies despite an irregular period. 

If your period is irregular can you still get pregnant

In this post you’ll learn how to get pregnant fast and manage the challenges presented by an irregular period, including tracking ovulation, timing intercourse, and other potential health complications.    

Yes! Getting pregnant is related to ovulation and as long as you are ovulating (even irregularly) you should be able to get pregnant.  Irregular periods don’t necessarily mean the absence of ovulation, they just mean you are not ovulating on a regular or predictable schedule.  

While this may make things more difficult than it would be for someone with regular cycles, it doesn’t make it impossible.  Sometimes it can be as simple as making lifestyle changes to regulate your period or may be as involved as fertility treatments.  Regardless of what helps you conceive, irregular periods do not spell the end of your pregnancy hopes.

What is an irregular period and how common are they?

Women are often told that the average menstrual cycle lasts 28 days, but in reality this is an outdated number based on averages.  What counts as a normal period varies widely from woman to woman.  A normal period may occur every 21 days to 35 days and typically lasts two to seven days.

An irregular period is defined as one or more of the following:

  • A menstrual cycle lasting fewer than 21 days or more than 35 days
  • A period that lasts fewer than two days or longer than eight days
  • Cycles that vary in length by more than seven to nine days (for example, 24 days one cycle and 42 days the next)
  • Having fewer than nine menstrual periods in a year- also known as oligomenorrhea
  • Going 90+ days without a menstrual period with no medical explanation (i.e. pregnancy, hormonal contraception, or menopause) – also known as amenorrhea

Irregular periods can also be characterized by abnormal menstrual bleeding, and was previously referred to as menorrhagia.

Symptoms of menorrhagia include:

  • Soaking through one or more pads or tampons every hour for several consecutive hours
  • Filling a menstrual cup every 2-3 hours
  • Needing to “double-up” on menstrual pads or waking up in the middle of the night to change your pad
  • Passing blood clots larger than the size of a quarter
  • Menstrual periods lasting longer than 7 days
  • Heavy menstrual flow that keeps you from doing things you would normally do
  • Symptoms of anemia such as tiredness, dizziness, or shortness of breath

Cycle length by itself doesn’t determine irregular periods and you may have one or more signs that your periods are irregular.  These signs can also change month to month for many women.  

How to get pregnant with irregular periods

Irregular periods don’t spell the end of your natural pregnancy hopes.  While some women with irregular periods will need to use fertility treatments, many take steps to get pregnant on their own through lifestyle changes or even tracking ovulation. 

Make healthy lifestyle changes

Improving your overall health before pregnancy is important for everyone, but it’s even more crucial for women with irregular periods.  These are some yet effective lifestyle changes you can make:

  • Quit smoking cigarettes
  • Quit consuming alcohol
  • Eat a healthy, balanced diet 
  • Get light to moderate exercise
  • Avoid excessive dieting or exercise
  • Take a daily multivitamin
  • Take folic acid and Coq10 supplements

These changes are affordable, good for your overall well-being, and may help you conceive.

Track your ovulation closely

There are numerous ways to estimate ovulation but irregular periods make it difficult to get accurate estimates.  Irregular cycles often cause issues using traditional methods like the basal body temperature method, checking cervical mucus, or the calendar method. 

Ovulation predictor kits (OPK) can also be faulty for women with irregular periods and tracking your period alone will not tell you if you’ve ovulated or not.  Using Mira’s fertility prediction kit is a more effective way to determine your fertile window.  Your daily levels of actual hormone concentrations are measured (with 99% accuracy) to detect when ovulation does (or does not) occur. 

Increase frequency of intercourse

It’s common for women to focus on conceiving during their two peak fertility days, but having sex more often can improve your chances of getting pregnant.  

To get pregnant fast with irregular periods, have intercourse frequently during your five-to-six-day fertile window.  Increasing the frequency of sex can boost your chances of conception.

Reduce stress and anxiety

Stress triggers hormonal imbalances and studies show that even short-term stress and anxiety can cause irregular and missed periods.  Reduce stress or anxiety by:

  • Learning stress management techniques such as deep breathing or meditation
  • Exercising regularly to increase endorphins
  • Getting consistent amounts of sleep
  • Seeking support through counseling or support groups

What causes irregular periods?

Medical conditions and health issues are the leading causes of irregular menstrual cycles.  Some require treatment, but others may resolve on their own.  Below are common conditions linked to irregular periods.

Polycystic ovarian syndrome (PCOS)

Polycystic ovarian syndrome (PCOS) is a condition caused by hormonal imbalance that often interferes with menstruation cycles and as a result, cycle regularity.  Hormonal imbalances can cause problems in the ovaries when the egg may not develop as it should or may not be released during ovulation as it should.  

You may still be able to conceive with PCOS.  Medication is sometimes prescribed to help with ovulation and you’ll likely need to see a fertility specialist for monitoring.      

Uterine fibroids

Uterine fibroids are noncancerous growths that can appear during childbearing years.  They are fairly common.  Some women have no symptoms while others may experience heavy menstrual bleeding, longer than normal bleeding, pelvic pain, and lower back pain.  

The exact cause of fibroids is unknown but genetics and hormones may play a role.  Most types of uterine fibroids don’t affect fertility and pregnancy – except submucosal fibroids.  

Pelvic inflammatory disease (PID)

Pelvic inflammatory disease (PID) is an infection that occurs when bacteria in the vagina spreads to the female reproductive organs through the cervix.  It is usually caused by sexually transmitted infections.  

Symptoms can range from non-existent or mild to severe.  Common symptoms of PID include:

  • abnormal bleeding or discharge
  • painful intercourse
  • fatigue
  • pelvic pain
  • fever

PID is usually treated with antibiotics but may cause infertility if not addressed.  If you have unprotected sex or multiple partners, get tested for STIs regularly to ensure you receive prompt treatment.

Weight can cause irregular periods in many ways.  Being either overweight, or underweight can impact your fertility by causing ovulation disruptions and making it harder to get pregnant.   Eating disorders, excessive exercise, and excessive weight loss can all cause irregular cycles.

Maintaining a healthy weight helps regulate hormonal balance and you can use an ideal weight calculator to find your target weight range.  This can help you set weight loss or weight gain goals for pregnancy.  

Ovulation and irregular periods

Ovulation plays an important role in fertility and irregular ovulation is the most common cause of infertility.  Irregular periods can signify that you are not ovulating regularly or having anovulatory cycles (cycles where you do not ovulate at all), leading to varying lengths in menstrual cycles.    

Ovulation symptoms for irregular periods

An understanding of the signs and symptoms can help you pinpoint ovulation even with irregular periods.  Both your cervical mucus and basal body temperature change throughout your cycle and those changes can help you determine when you ovulate:

  • Cervical mucus becomes stretchy and clear, like the consistency of an eggwhite
  • Basal body temperature (BBT) also fluctuates with the onset of ovulation and tracking this spike lets you know that ovulation is occurring

How to track ovulation with irregular periods

The best way to know for sure if you are ovulating is through hormone tracking and testing.  Digital fertility trackers like Mira can determine the exact numerical value of LH and FSH in your urine to predict when you will ovulate with scientific precision.  If you can spot the LH and FSH surges in your hormone patterns, you can determine when you are ovulating, even if your ovulation is irregular.    

FAQs about irregular periods and pregnancy

We’ve done our best to answer some of your most common questions about irregular periods and pregnancy.  

When do I ovulate with irregular periods?

Every woman is different and her cycle (and ovulation) will be different as well.  While hard to predict, you can always confirm ovulation through hormone testing and tracking.  

How hard is it to get pregnant if I have irregular periods?

Women with regular periods are four times more likely to conceive than women with irregular periods.  However, irregular periods don’t automatically mean infertility and with consistent tracking and timed intercourse it’s still very much possible to get pregnant.

When should I have sex to get pregnant with irregular periods?

You have the best chance of conceiving during your fertile window and to know this you’ll need to know when you ovulate.  Tracking your cycle and timing intercourse during your fertile window is one of the most important things you can do to boost your odds of conception.  

When should I take a pregnancy test with irregular periods?

Ideally you should wait until the first day of your next expected period to take a pregnancy test or at least two weeks after ovulation.  With irregular periods that can be difficult if you don’t track your cycle or know when ovulation takes place.  Taking a pregnancy test too early (before the two-week wait) can lead to a false-negative result.  

Using a product like Mira when you are trying to conceive can help you know when you ovulate by tracking your precise LH levels.  Combined with AI personalized cycle prediction, it can help ensure you test at the right time. 

Is irregular periods hard to get pregnant?

Yes, women can get pregnant with an irregular period. However, the ability to get pregnant decreases significantly. The disadvantage is ovulation becomes difficult to determine. The pregnancy success rate of a healthy woman with a regular cycle is 30%.

What are the symptoms of pregnancy for irregular periods?

Signs of pregnancy when you have irregular periods.
Extreme tiredness..
Morning sickness (or nausea and vomiting at any time of the day).
A frequent need to urinate..
Swollen and sore breasts..
Light spotting..
Bloating..
Moodiness..
Cramping..

Does irregular periods mean infertility?

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.