Depo provera is not a very good birth control in terms of your health. I was on it for 3 years with no problem, but I have heard the horror stories from my friends of what it can do to your body. My doctor told me it is not safe for teens to take it more than 3 years because of the bone density issue, that was why I was taken off of it. I know depo is a hell of a lot easier then taking pills everyday but there are other forms of birth control like nuva ring which you wear for 3 weeks and take it out to have a period. And patches, where you change them every week for 3 weeks, and then wear nothing to have a period. There are also other long-term birthcontrols like cervical caps which I know nothing about but I don't think they are reccomended for teens. Just talk to your doctor about different birthcontrols, she will give you the run-down on EVERYTHING!