Pre-pregnancy I was a 36C, and know that my cup size increases when nursing. I ordered an XL based on the size chart, however the band was huge on the set of 3 I received.  I returned it and purchased a L instead, and the band was still too big.  At that point I returned them again and decided to try other nursing bras on Amazon before trying the next smaller size.  The cups seemed ok, and the clips were secure,  but easy to undo with one hand.  It is unfortunate that the sizing was so off because the price was great for  a set of 3.