It’s time to squash that age-old myth: Your period doesn’t protect you from pregnancy. There are a couple of reasons why. 

You get your period when the ovulated egg (the egg released from your ovary to be fertilized) has not been fertilized, and the lining on the Uterus which had been prepared for pregnancy breaks down and is shed in the form of blood. 

However, some women may bleed in other situations. A common one is during ovulation itself, and women mistake it for their period. However you are at your peak fertility when you ovulate. So if you have sex during this time, it could actually make you more likely to get pregnant. 

In addition it’s important to remember that sperm can sometimes survive in the body for up to 7 days after you have sex. This means it may be possible to get pregnant soon after your period finishes if you ovulate early, especially if you have a naturally short menstrual cycle. 

Be sure you know your cycle well, so that you can be sure you are bleeding because your period date has come (whether it be quickly or at a prolonged date).