I'm petite, but have large breast's and normally wear a 32D or DD depending on the brand.  Since I'm nursing (#3 btw) I ordered a 32F and the cup size is perfect.  This bra's band does run large so be sure to order a size smaller than what you would normally wear.  I was unable to do this as they didn't offer a 30F.  Because of this I can tell that it won't fit once the rest of my preggo weight comes off as I'm already using it on the tightest setting.  In the meantime it's great and super comfy!

I gave it 4 stars instead of 5 because the straps are not as depicted in the picture.  I cannot wear this bra with a tank top because the straps are wide and industrial looking.  Another review stated that it had "normal" straps so it could be worn w/tanks and that's what eventually won me over so that was a little disappointing, but I'm not sending it back because we live up north and it will be worn mostly during the fall/winter months to come.  Otherwise the bra is very pretty, and like I said before, the comfort is outstanding!!

I've tried a TON of nursing bra's and this is by far the best.  Well worth your dollar!