Hey Stasia, I think everyone is right when they say it is likely colostrum. Midway through my pregnancy, I started complaining to my husband that my nipples were really dry. They weren't irritated or painful, but they were really flaky and I could see these big skin flakes when I wore black bras. In the shower, I could pick off huge chunks of them!
Well, eventually I realized it wasn't skin! It was colostrum!