How do you ask for a bigger bra size?

It might feel embarrassing but ask the lady at the store. She can measure you and give you the right size. The majority of all women have the wrong size on because they wont ask a professional. They are only happy if you ask and are glad to help. When growing up you will probably change size more then once so do yourself a favor and ask for help at the store. I'm sure she wont mind if you ask her if you can talk and move away a bit from the other customers so they can't hear you if you find it embarrassing. They were in your position once.