I ordered a small and it fit me perfectly. It took about 10 day to get delivered. The back of the dress is white and quite see through so I definitely recommend wearing nude undergarments with this dress!
It's not actually too small, it fits, it's just a spandex material making it skin tight, and then it's also really short on me... I'm 5'8" and my butt is definitely out in this if I'm not paying attention. But other than that super cute!! I love it!