TeenHealthFX is concerned that you have not gained weight or developed in any place since you were 10. The concern has nothing to do with your breast size but rather during the course of puberty your body should go through changes that involve growth. It is possible that you have gone through the necessary stages and you may have not noticed the difference because you tend to be small in stature. In any case your doctor would be able to tell you if there is a problem, so mention your concern next time you talk to your physician.
A small lump in your breast and nipples turned inward are signals to your doctor to monitor for the possibility of breast cancer. Although it rare at your age, there is a chance that you could be at risk if there is a strong history of breast cancer in your family. If you are really concerned talk to your doctor and ask questions. You may want to make a list of questions beforehand since you may be a bit anxious during the visit and might forget something important. Learn as much as possible about your condition as a way of reliving the uncertainty, which tends to fuel fears.