Patagonia Periwinkle dress

I absolutely LOVE this dress but don't have the boobs to fill it in. I've tried this dress on so many times thinking it would fit me better... but alas, the ladies are just consistent. lol. never worn. just tried on. incredibly soft material. I wear mediums and the rest of the dress fits perfect... but the upper part is baggy on me. I am 5'7", 160 lbs, and a 34B... I hope this helps with sizing. ♡