Quoting Coltin's Mama ♥:" Oh wow thats great to know, my doc didnt say a word about it, its like because i was 17 they wanted to give me something ASAP to keep me from having another baby.."
Don't take this the wrong way, but when I was younger, no one felt like they had to tell me about these things either. I didn't get options so I didn't know about them. As a mother, you've probably already learned that choosing things for your health and well-being means making a lot of decisions based on personal research. There are PLENTY of women here that can tell you about B/C options that aren't as damaging. Check the Sex and Relationships Forum...there is a sticky there that talks about birth control options.
If you're okay with depo, then that's completely fine, but I just think you're too young for it honestly. You want to get something that will keep you reproductively healthy. You're not even done growing at 17!