Please help me, am I pregnant

Ok so I’m on the pill and try super hard to take it at the same time everyday and usually pretty good at it. My pack was up on Sunday and usually I’ll start my period that Monday/Tuesday. And I still havent gotten it, there was slight dark brown discharge and spotting but nothing a pantiliner couldn’t handle and slight cramps. My boyfriend and I never use a condom and sometimes he’ll finish in me, but like I said I’m on the pill. Is there any chance I could be pregnant?? My periods neverrr been late since I started taking the pill a couple years ago.