Hi Sarahlou,
I had 300cc unders four months ago. I was measuring a 32a before (or maybe smaller) and now i’m a 34d. It’s really hard to predict what size you will end up, they advise 150cc per cup size. But its not an exact science. If it helps, i really don’t think i look like a d. So i wouldn’t worry about them looking too big, because in clothes you will look fine! But if you’re worried i would go for a 300 or 340.
good luck x