I wear the same size and I also get mine at Nordstrom. Even then, the girl brought me a whole armload of bras and I really only fit well and liked one style. This is the style that I'm sticking with for now; others in the same size were either too big in the cup or so tight that I couldn't wrestle my way into them.

It really, really helps to have a professional measure but having said that--I've had measurements done by a differentbra-shop employee and was very unhappy with the size she was trying to stuff me into (huge band size, small cup). She was doing it because her shop didn't carry a G cup, so she was trying to move me up 2 band sizes AND smash me into a minimizer. Ick!