Anyone familiar with these? I got my order today, which contained two of these, both size 16. They fit pretty well at this size. But since they're 100% cotton, I am a little anxious they might shrink. I am also concerned that if I exchange for the 18, they'll be gigantic, and will require shrinkage. I don't typically toss my clothes in the drier other than briefly to dewrinkle on extra low...but I don't know if that's enough to shrink a cotton top. Thoughts?