As you have already seen, your photo did not successfully upload, so a specific answer regarding your breasts cannot be provided, but as far as size and development, by age 19 it is most likely that your breasts are as fully developed as they are going to be. You can certainly consult with your pediatrician, family doctor, or gynecologist in that regard. If you are serious about considering breast augmentation, your age is certainly an appropriate one in which this can be considered, and you should seek out a board certified plastic surgeon who will perform an evaluation and let you know your options. The best way to determine which breast implant size would be best for you is by first finding out your specific wishes not only with words or letters as in cup size or “not too big” or “natural”, but also with a visual understanding of what you hope to look like. This can be accomplished either with photographs of patients whose breasts and body type look like you, or ideally with photos of patients not only whose breasts and body type visually are similar to yours, but are also a similar height, weight, and pre-operative breast size. In our own practice we have provided that unique functionality on our website to accomplish exactly that. Unfortunately the most common reason for a woman to be unhappy after her augmentation is feeling as though she is either too big or not big enough. Thankfully, in our practice this is rarely a problem because implant size selection is what we spend most of our time discussing and determining. I do not place the onus of selecting the breast implant size on my patients since they are coming to me for my advice and expertise, but I do ask my patients to be as specific as possible about their aesthetic goals and I then advise them accordingly. Again, I would advise you to seek the advice of a board certified plastic surgeon experienced in breast enhancement surgery and make sure that your own sense of aesthetics aligns with that of your plastic surgeon. Your idea of “natural” or “pretty” or “proportionate” might be different from your plastic surgeon’s and it is very important for you to feel confident that you are both of like minds as far as the goals. Best of luck to you and I hope you are successful in achieving the enhancement you are seeking.