For a 34B, my opinion is that you should definitely go with the larges, or possibly even the contoured larges.
On an unrelated note, if I were you, I would take down the pictures you have posted of your breasts, or post pictures with the nipples covered/edited away, because you are under age. It's not a good idea to post pictures like that of yourself anywhere online, even for something like the Noogleberry. It could not only have negative impact on you, but also anyone who happens to view your thread or even the forum itself. I'm sure you understand!