I was a 34C, and have grown to a 34D in my 2nd trimester, and I ordered a M. The sizing on these worried me originally, but now makes sense as the cups are a very soft, stretchy material that can stretch to fit your breasts as they continually change size and shape during pregnancy and breastfeeding. They are very soft and comfortable and despite no underwire and feeling quite thin, they actually offer a fair amount of support. The padding is light (can also be easily removed).The clip is easy to use to pull down the cups for access for breastfeeding, but I'll be using these for rest of my pregnancy and then breastfeeding with these later.I'm pretty impressed by these, and the colours are pretty too. I'd definitely recommend to try these!