Originally bought a small based on the sizing chart (I still fit in most 34Bs, sometimes 36B depending on brand) and it was way too small, couldn't clasp it. I returned it for a medium and it fits much better. Some reviews said to go bigger, while some said to stick to the sizing chart so hopefully my review will help someone that was in the same dilemma as I was and go up a size of your rib cage is in between sizes. At 37 weeks, there seems to be enough room in the cup for when my milk comes in. I like the feel of the fabric and will most likely buy a second one once the baby comes and I make sure that I still like it while actually nursing.