What if you have sex the day before you start your period

I was supposed to be ovulating this week with the day being Friday the 13th. I started my period today and my fiancé is wondering if having sex the night before increased the chances of us getting pregnant... I said no I don’t think so... everything I read said during or towards the end of your period... but nothing answered before. can anyone help us? We are new at this whole actually trying to make a baby thing.