I've been on the depo provera shot for over 2 years, without so much as a spot of bleeding from the day I got my 1st shot - even on times when I've gotten my shot late, I've never had a period or any spotting. However, I just got a period, quiet heavy, and I'm not sure if this is cause for concern. It's been about 8 weeks since I got my most recent shot - has this happened to anyone? Is it cause for concern? I'm 20, iif that matters