I am 15 I am 16 in 3 months. My breasts seem to be the same size for as long as I can remember. All my friends have bigger chests than I do. What should I do?

Well you should wait they will probably grow when you are 16 most things happen then as I have read in books ;)

Its possible you have reached your size. Its also possible, you may have a growth spurt. You can't go by how others develop as each person is different.

What size cup are you?

I never got any bigger from about 13 on (I'm now 67). C'est la vie. Just stay friendly and nice to people and it really, really, really won't matter. Of course it sort of matters, sigh. But you have to convince yourself that it doesn't.