I'm trying to figure out the exact day I got pregnant. I had sex with my boyfriend sept 8th then I saw my ex and we had sex sept 10th then I had my period sept 12th I didn't have sex again until sept 25th with my boyfriend when did I get pregnant?

Unless you had certain types of medical assistance to become pregnant, you won't know the exact day that you conceived.

However, given the information you provided, odds are greatest that you got pregnant from the sex on Sept. 25th.

This is because most women will not ovulate right before a period... it can happen, but it is not the norm. The sex on the 25th of Sept. puts you right where the average time for ovulation would occur with a period starting Sept. 12.

If you need to know for certain who the father is, you would need to have a DNA test done once baby is born.