Spots on chest?

When I was in high school, I had the same problem. In fact, I had a relatively mediocre acne prob. Even my back was covered in little bumps. As of late, I've noticed some bumps that remain from the high school days on or around my chest and cleavage like yourself, but there aren't all that much now. I've even had one of the bumps turn out i.e got inflamed. I think the best healer for you is time. You're under 18 so you're still young and puberty ,whether you wanna believe it or not, isn't quite over for ya just yet hehe. My thinking is that those will eventually go away over a period of time; maybe not entirely but time should remedy that sufficiently. If time doesn't work, then I'm not sure what else will. Good Luck still!