QUESTION ABOUT MY BODY FAT?

im 15 years old. my bra size is 34a which is in fact very small compared to other girls that are my age. ive been this way since i was 12 i am just wondering if i will ever get bigger boobs and a bigger butt. people say i should eat and ill retain the body fat but i did and all my fat went to my thighs and made me look fat. what should i do, will i ever get bigger?