Hi So I Missed The Last Active Birth Control Pill

Hi so I missed the last active birth control pill in my pack and had unprotected sex with my boyfriend that night. I usually take my pill at 10:00 p.m. and I didn't take it until about noon the following day. I couldn't take two as the pack prescribed because it was the last one and the rest of my pills were else where. I've been on my inactive pills and had spotting the first couple days and now I'm bleeding very heavily, more so than I ever have even before I was on birth control. Is it possible that I'm pregnant or could it be something else?