Does plan b make your period late?

I was suppose to have my period yesterday and I took plan b during my first day of the sugar pill because the day before I was 10 hours late on my birth control. But I still haven't gotten my period and my boyfriend did finish in me. Is there a chance of me being pregnant? Also when should I start taking my normal birth control again. (I'm on birth control bc I regularly don't get my period, therefore the pill makes my period occur.)