VV...
I usually am in tears anytime I go bra shopping because I am such a very very very very small chested girl. ( I wear 36A, but a small one, something between a 36AA and 36A!!)One day a few months ago I pumped up my psyche and went to all the department stores in the California/Lexington park area where I live and tried on every single 36A bra whether I thought it would fit or not. Finally, after several hours running in and out of a dressing room, I emerged with 2 types that fit well enough from JC Penny in Wildwood.
I know that in a lot of things I don't need to wear a bra, but I hate the no bra wearing look in some clothes I have because I think it looks trashy and slutty.
Anywho, whatever size you are, you may have to do the same thing. I know my sister does even though she is quite a bit larger than I (38D, I think... now how did that happen???)
Good luck!