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Trying to conceive · 4 min read

Irregular periods and getting pregnant

If your cycles are all over the place, it is natural to wonder whether you can still get pregnant. The short answer is yes, but the timing takes a bit more detective work. Here is how to work with an irregular cycle, and when it is worth seeing your GP.

HC
By the HerCycleCalc editorial team
Written in plain English and checked against NHS guidance. Last updated 3 June 2026. How we check our content.

Can you get pregnant with irregular periods?

Yes. As long as you are ovulating, you can conceive. The catch is that irregular cycles make it harder to predict when you ovulate, and that fertile window is the part that matters most. So it is less about whether you can, and more about pinpointing the few days each cycle when it is possible.

Why cycles become irregular

An occasional off month is normal. More persistent irregularity has a range of causes worth knowing about:

  • Polycystic ovary syndrome (PCOS), a common cause of irregular or absent periods.
  • Thyroid problems, both over- and under-active.
  • Significant weight change, being under or over a healthy weight, or sudden loss.
  • Stress and big lifestyle changes.
  • Perimenopause, as you move towards your forties and fifties.
  • Recently coming off hormonal contraception, while your cycle settles.

Because some of these also affect fertility, an irregular cycle is a good reason to have a chat with your GP if you are trying to conceive.

How to track ovulation when cycles vary

Calendar predictions lean on a regular cycle, so when yours is not, your body's own signs become more useful than any app:

  • Ovulation predictor kits detect the hormone surge that comes just before ovulation, which is handy when you cannot guess the day. You may need to test across more days of the cycle.
  • Cervical mucus turning clear, wet and stretchy is a reliable, free sign that ovulation is near.
  • Basal body temperature, tracked over a few cycles, can show the small rise that follows ovulation and help you spot your pattern.
  • Regular sex, every two to three days through the month, is the simplest fallback. It keeps sperm present without you having to catch one exact day.
Track your cycle and fertile window
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When to see your GP

It is worth booking an appointment if:

  • Your periods are very irregular, very far apart, or have stopped.
  • You have been trying to conceive for a year, or six months if you are 36 or older.
  • You have other symptoms such as excess hair growth, acne or weight changes that might point to PCOS or a thyroid issue.

Your GP can run simple checks, help find the cause, and talk through options. Irregular cycles are common and often very treatable, so it is not a conversation to put off.

Frequently asked questions

Does PCOS mean I cannot get pregnant?

No. Many people with PCOS conceive, sometimes with support to encourage ovulation. It is worth seeing your GP early if you suspect it.

How can I tell if I am ovulating at all?

Predictor kits, cervical mucus changes and a sustained temperature rise all point to ovulation. If you see no signs across several cycles, mention it to your GP.

Should I still take folic acid?

Yes. The NHS advises 400 micrograms of folic acid daily while trying to conceive, whatever your cycle looks like.

The bottom line

Irregular periods make ovulation harder to predict, not impossible to reach. Lean on your body's signs and ovulation kits, have regular sex through the month, take your folic acid, and see your GP if your cycles are very irregular or you have been trying for a while. There is usually a clear reason, and often a clear way forward.

Sources

Read next: How to get pregnant · Understanding your fertile window.

This article is general information, not medical advice. For advice about your cycle or fertility, please speak to your GP, or see nhs.uk.