Is it normal if the breasts of a 17 year old girl get smaller? bra size used to be 34c now is 32c or 32b within a few months. no weight loss or gain.

It can be...: Without any other symptoms or information, this is likely normal. Body fat distribution (not just total mass) is determined by a very complex interplay between hormones that are very actively changing before, during and after puberty. So as the body changes/matures, the body fat (aka adipose) distribution may also change. If you're worried, though, go see your doctor, they can help.