You should measure yourself and make sure of your bra size.

Well i am 15 aswell, a size 10 D and i have been wearing a push up bra pretty much everyday for 2 years. The first thing you should do is decide whether its a cup size or a strap size that needs changed, if your boobs kind of hang out a bit near your armpits then you probably need a bigger cup size, but if its just tight you may only need to go up another strap size. When you go to try them on, take a size A in a bigger strap size and a B. Also remember that different stores and brands have different ideas on bra sizes for example; a size 10D for me in one brand or store is sometimes a 12C in another. You need to get a proper size, a bigger sized bra does not make you look larger, you can see the gap when you bend over, also theres nothing to be 'pushed up' if it is to big. Once you have your size sorted you want to get a colour the same as a bra you already own so your mum wont suspect. One more thing, it is a very weird feeling to get used to but once you are familiar with one it gives you so much more confidence :) Goodluck

its called breast reduction surgery. it is possible. and you dont need to have cancer to get it. the price vary so just with your doctor. typically they do it for women with back problems, but anyone can have it done.