pill and unprotected sex HELP

So when me and my bf had sex, he came inside me. Which at the time I thought was okay because I am on the pill and I have been for a good few months and I don't miss them and take them pretty much same time every day (my doctor said no more than 3 hours apart). I finished my pack on Saturday so my period should be coming anytime now and I'm starting to get worried that I'm pregnant..? Help please!!!