Just Some opinions other then my family and boyfriend...?

im 18 years old and have been wanting a augumentation. i went for my consultation and everything and i got the money...my siuatuion is i have always been uncomfortable with my chest...im barley an a. my boyfriend is the only one i have shown not even my mom! i just want some advice and other peoples opinions on maybe sizes and advice from others that have done it. the doctor reccomended 350 cc im doing 400 i think im worried becasue i woman at my job got hers done she was flat and she got 450cc...ADVICE???