When did you guys stop growing?

I'm 15 and currently 5'6". Is it too late for me to keep growing? I know I've read and heard numerous people say "stop worrying about it" or "don't pay attention to it", but really you tend to have an advantage in the real world with physique and appearances. Do you guys have any advice on increasing height?

I know it's mostly genetics, but are there any stretches or exercises that can help?