Pill Misunderstanding

So I went to my doctor to get put on birth control, but I was so nervous the whole appointment that I didn't realize she told me to start the day of my next period or the Sunday after. I started the pill as soon as I got the prescription filled and had unprotected sex (he pulled out) everyday for a week. My period is now 5 days late. Is it because the birth control stopped my period or is there a chance I could be pregnant?