Maybe this is a stupid question BUTTT...

Okay so my husband and I had unprotected sex a few days before my period. Obviously no one can tell if their pregnant that fast. So my question is, do you wait till the next period to tell if your pregnant? Like if your period still came a few days after the unprotected sex can you still possibly get pregnant? I'm just thinking logically no but I just don't know! It's not a super big deal I'm just curious now.