I've been lifting since I was a sophmore in high school. I'm 27 now, and the thing I'm most grateful about is that I didn't start using gear until I was about 23. Since I put in a lot of natural time, my body thinks its job is to be big and strong. So, when I go off gear, it doesn't revert back to a scrawny turd like I was in High school.
If you start this early, you WILL rely on gear for growth for a long time. My vote is to bust your ass naturally and wait. I know a lot of bodybuilders, pro and otherwise. I also know a lot of guys that started juicing at really young ages. I've learned that if you do them now, you will regret it forever I promise.