Hey there, Ive been on the depo provera birth control shot and have been for about two years and have never had any problems, I'm an 18 year old and only take caltrate every day on top of the depo shot, but nothing more other than allergy medication that I've taken for years, so usually at the end of my three month cycle of depo usually about a week or so before I go in for my shot I have slight spotting that happens and light cramps that don't bother me much, it has just concerned me that for the past maybe week after I got my shot (October 5th) I have randomly been spotting, it's not everyday though. I also get light cramps while it happens and its not usual so I'm a bit concerned.