Could The Size Of Breasts Be Related To Hormonal Changes In Body?

Hello, I am a female 5ft3 122lbs and i will be 22 in May. Last christmas even though i d been loosing weight my boob size hadn t changed. I had gone from a 36F to a 32G. But a few months later when my weight was stable doing the same amount of exercise with less cardio, my boobs were fluctuating between FF and GG cup size with no weight change and no band change. Now my boobs have shrunk down to an F cup same band and i m worried that they will keep shrinking. Is it possible that its a hormonal concern? Is this normal? Will they go back to normal? Thank you very much