Hi, I'm a 19 year old female and I have been bleeding for 3 months straight already. Yes I'm on the birth control shot but I don't think I suppose to bleed everyday. Some days I bleed heavy and some light. I was wondering if anyone knows the cause of this.

Yes this is normal, they don't tell you this but that is VERY common. I did the same thing, and finally quit the shot because of it. This varys from person to person, but you can continue to "spot" or even have periods for months or years after starting the shot. It is nothing to be worried about unless you are having other problems. In which case you should go to doctor and talk to them about it. But this is not only associated with the shot, but also the pill, it is a reaction to the hormones and stuff in the BC and your body getting used to the change.