Pregnancy chances?!

So my boyfriend and I had sex last week and the condom broke and he felt it right away and put on a new one. I've been on birth control for about 3 months and messed up a pill in the first one but made it up. Also he didn't finish in me. 3 days later I got my period but I was paranoid it was lighter than usual. Could I still be pregnant and that maybe be a false period?