When can you get pregnant after your period?

If you have a regular period, your period is likely to come every 26-35 days. Your cycle can change from month to month by a few days. You are most fertile mid way in your cycle when you ovulate (so for most people this is about 2 weeks after the first day of their period, if their normal cycle is around 28 days). You can never 100% know when you are going to ovulate but you can roughly predict it if you have regular periods.

You are more at risk of pregnancy on the days leading up to ovulation, and are at a very high risk of pregnancy on and around your predicted day of ovulation: this is called your ‘fertile window’.

It is important to remember that sperm can also survive in the body for up to 5 days, so you can still get pregnant if you have sex on a day you do not think you are ovulating or you are in your fertile window.

If you have recently been on contraception, or taken the emergency contraceptive tablet, this may also affect your cycle and you may have had a delayed or early period.

Periods can also be disrupted by factors such as stress, sudden weight loss or weight gain, travel (such as long haul flights) and strenuous exercise, so this means your cycle may not be as predictable as you think it will be.

As you can never know for sure when you will ovulate, you should consider yourself at risk of pregnancy at all times during your cycle, with a much higher risk around your fertile window.

Written by Dr Paula Baraitser. Medical Director

Last updated at: 08 March 2022