I switched birth control from depo-Vera back to the pill at the start of August. I was out of town with my boyfriend and accidentally forgot to take my last Saturday pill of that pack, and later that day had unprotected sex. The next day I immediately took the Saturday pill and Sunday pill at the time I normally do, but he was so stressed out he bought me plan B. Even if I hadn't had the plan B, could I have still gotten pregnant just by missing one pill?