pregnant right before period

I know how everything works and you have to ovulate to get pregnant but just out of curiousity how likely is it to get pregnant a week to 5 days before your period? My bf came in me while we were having really good sex for my birthday this past weekend and we decided not to get the morning after pill. I honestly don't feel like I would be lucky enough to get pregnant anyways! If I didn't have bad luck I'd have none!