i measure 32 but always wear 34 in bras otherwise it feels WAY to tight so i got a medium/34 macom, it fits good if ur a small/comfy 32 though id say get that coz ur back doesnt swell n the cups stretch sooo much xx
im a 30 and i brought a small its very comfy and i love it, i also brought a xs which is ok but at times i feel its a little tight so i have to give my boobs a rest from it, i would def buy the small. hope this helps xx