Enquiry Please Help?

Im 17 years old and do a lot of sport - athletics, football, netball. I'm training most days a week whether it be for long periods of time or just a short netball match. My are only a 32A and my sisters a 34B. If i stopped sports would it be likely my continued to grow or is it too late for me. I hear its just fat so i presume i just need weight or is their only limited time?