Can I get pregnant on my period?

The short answer is yes! If you want to understand a little bit more, including the basics of male and female fertility, check out this short animation. It explains the fertile window, so you truly understand your own body and when it’s capable of conceiving, as well as the lifestyle factors that can affect natural fertility. Having kids is something we often take for granted, but one in seven couples struggle. Understanding a little biology can go a long way in helping protect your fertility and avoid unwanted pregnancies.



This animation was written by Grace Dugdale and created for the British Fertility Society’s Fertility Education Initiative, which is chaired by Adam Balen



Who thinks about having kids when you’re at school?

The thing is, what you do to yourself now affects your future health and fertility.

Take Flis and Louis. They haven’t even met yet, but one day, they’ll get together and want to start a family. They can’t see into the future, so they don’t know that they’ll struggle.

Right now though, Flis has just had a one-night stand. The condom split in the middle of sex … and she’s worried.

She was technically still on her period. Well… still spotting anyway. You can’t get pregnant on your period, right?

Turns out you can.

The fertile window is basically the few days every month when it’s possible to get pregnant. And for humans, that’s around 6 days … usually around the middle of your monthly cycle.

Girls have 24 hours once an egg is released from the ovary for it to be fertilised by a sperm cell before the egg starts to break down.

Sperm can survive for around 5 days inside a girl’s body, so that’s where the 6 days comes from. 6 days of what’s usually about a 28-day cycle.

So depending on how long your period lasts and when you ovulate – in other words when the egg is released – yes, it’s technically possible to get pregnant when you’re on.

Because the monthly cycle and ovulation can change from month to month when you’re young, you have to assume you can get pregnant at any time and be really strict about contraception, or you’ll be caught out.

So, understanding your body is a skill for life. For now, when you don’t want to get pregnant, and for later, when you might.

When you do want to have kids, knowing your fertile window is important as it gets harder to get pregnant as you get older.

Girls are born with a fixed number of eggs that are continuously lost over time as you age. So the number of eggs and also the quality goes down as you get older.

That’s why the main thing that affects your fertility is age. And after you’re 35, fertility starts to decline fast, though sometimes things can go wrong sooner.

Smoking makes you lose your eggs more quickly, for instance, and having a bad diet or being overweight can affect egg quality. Because eggs are in your body for life, having an unhealthy lifestyle will affect them over time, and your teenage years are really important.

Louis isn’t off the hook either, even though sperm is being freshly produced in the testes all the time – as smoking, cannabis, being inactive, junk food and alcohol can all affect sperm health too.

So by the time Flis and Louis meet years later, all these things they don’t notice having an effect now, build up over time to cause big problems. Plus, they don’t realise that waiting 5 years before trying for kids might mean they’ll leave it a bit too late.

One day they’ll be in a fertility clinic wishing someone had taught them this stuff at school….


“I had my NHS scan last week and confirmed my due date, it feels like a dream come true!”

Note: This patient conceived naturally after failed IVF cycles and multiple miscarriages.

“Words cannot describe the gratitude and in indebtedness we feel for helping us to create our little miracle, our beautiful baby boy.”

“We would like to thank you so much for the wonderful care and support given to us whilst seeking treatment with you. We are so happy that you gave us the chance to be parents and welcomed our wonderful son into the world.”