please help!!

So my period started last Saturday (5/6/17) and that was the day I first started my birth control pills. I've been taking them at around the same time everyday (never more than 45 minutes late). Today would be the 5th day that I've been on birth control (5/11/17) and I'm still bleeding a little bit from my period. Today my boyfriend and I had unprotected sex and he finished in me, almost immediately I peed it out as much as I could. We're not ttc at all right now because we're both still young. I just want to know what are my chances and likelihood of possible pregnancy?? I've heard some say BC becomes affective right away if you start the day of your period, I've heard some say you have to wait 7 days or even month for it to kick in. I would just like some opinions and help on what my likelihood is. Thank you so much 💘