Although many products (from special creams to exercise techniques) claim to boost breast size, you should save your money: They don't work. The truth is that the only way to permanently change breast size is cosmetic surgery.
Most doctors won't perform breast enlargement surgery until a girl reaches 18 because the body takes time to develop and some girls develop (and have changes in the size of their breasts) later than others. Even after 18 there are certain physical and psychological risks involved with breast implants.
Everyone goes through times when they don't like parts of their bodies. These feelings are part of normal development and the process of adjusting to our changing bodies. Even girls with large breasts can be unhappy about them. Some find that their backs or shoulders hurt or that the large breasts attract unwanted attention and they may wish their breasts were smaller.
If you're unhappy with the size or development of your breasts, talk to your doctor or gynecologist, who can probably reassure you that you're developing normally.
Although we can't reply personally, you may see your question posted to this page in the future. If you're looking for medical advice, a diagnosis, or treatment, consult your doctor or other qualified medical professional. If this is an emergency, contact emergency services in your area.