Birth control pills

I had unprotected sex Sunday Sept 4.. with NO pull out and I hadn’t had a single pill in my system for a full 8 days… 4 of those days was my “period” but I read up that the period you get on birth control isn’t really a period but more so “withdrawal bleeding”… I’ve been feeling nervous about taking my pills the past week. Is there possibility of pregnancy? Should I continue taking my pills or stop?