A slight tangent, but if you've got a TK Maxx nearby it's usually worth a pop in - they often have sports bras mixed in with the normal bras (usually shock absorber, which luckily I get on well with), and it's a bit of a lottery of course whether they'll have your size/style but they are generally hugely discounted!
You also have a chest circumference.. Therefore you do have a bra size, it just so happens that the same cup size at different chest diameters doesn't have the same 'breast volume'.Most women have no clue what a bra size means, and they cling to the concept of a 'bra size'... You dont have a bra size. You have a 'Breast volume'.
I'm a guy, but unless you understand and acceot that a 34B is the same volume as a 32C, you probably need to learn a lot.