Period/Birth Control

I've been on the shot for a year and in the last 6 months I started to bleed every day. I had a week before October 11 and up to a week after to renew the shot but I never did. My boyfriend and I had sex on the 22nd. Yesterday and today my period has started to go away. I've only bled for about an hour each day since yesterday. Is that the shot wearing off or might I be pregnant?