Whats the pregnancy risk if you have sex on your period?

Low but not zero: You can get pregnant when you ovulate. It would be rare to ovulate during a regular menstrual cycle. However, some people have irregular bleeding can can be ovulating while they are bleeding to be safe, use protection.

Depends.: It should be low, but it depends on your age (the older the lower the risk), your period's predictability/regularity and your luck. You could ovulate early and still conceive from sex during your menses because the spermatozoa survive for up to 5 days in your genital tract.