So, when dd was nursing today, she unlatched and I saw what looked like a yellow blister on my nipple. Later, when she was sleeping, I took a look, and it was hard, so not a blister. I pulled on it, and it didn't hurt, and it eventually came off. I thought it might be dried milk, but does BM dry clearish yellow? Could that have been a plugged duct? It never hurt, but if I had left it, maybe it could have? I have no idea, and it doesn't sound like anything I've read about in the breastfeeding books.