Can you get pregnant on your period?

Bottom lineYes, you can get pregnant from sex during your period, though it's less likely; because sperm survive up to 5 days and ovulation timing varies, sperm from sex near the end of your period can still be present when you ovulate, especially with short cycles (around 21 to 24 days), long periods, or irregular cycles. A period is not a reliable safe window, so use contraception if you're avoiding pregnancy, and note that ovulation or breakthrough spotting is sometimes mistaken for a period.

Yes, you can get pregnant from sex during your period. It's less likely than at other times, but a period is not a guaranteed safe window.

Why it's possible

Two facts combine to make it happen:

• Sperm survive up to 5 days inside the reproductive tract.
• Ovulation timing varies, and some people ovulate early.

So sperm from sex near the end of your period can still be alive several days later when an egg is released. The closer your bleeding is to an early ovulation, the higher the chance.

Who is most at risk

• Short cycles. If your cycle is around 21 to 24 days, you ovulate earlier, sometimes just a few days after your period ends. Sperm from period sex can easily overlap with that.
• Long periods. Bleeding for 7 days or more leaves less gap before ovulation.
• Irregular cycles, where ovulation timing is hard to predict.

A common mix-up

Some bleeding isn't a period. Light bleeding around ovulation (spotting) or breakthrough bleeding can be mistaken for a period, and sex during that bleeding lands squarely in the fertile window. If you're tracking to avoid or achieve pregnancy, knowing whether bleeding is a true period matters.

What this means for you

• Trying to avoid pregnancy? Don't rely on your period as protection, especially with short or irregular cycles. Use contraception.
• Trying to conceive? Period sex rarely lands in the fertile window, so focus on the days leading up to and including ovulation instead.

Know your own pattern: map your cycle with the Menstrual Cycle Calculator, find your fertile days with the Fertile Window Calculator and Ovulation Calculator, and learn the body's signs in our guide to ovulation symptoms.

Femora predicts your fertile window from your own logged cycles, so you can see exactly when pregnancy is and isn't likely.