I'v e heard of sharp breast pain in one breast or both being connected to breastfeeding during pregnancy. And that was my experience as well.
With my first pregnancy, I had sore breasts but no sharp pain. But with my second, when I was still nursing my first, I had sharp pains. I wound up weaning due to decreased milk supply and I had sharp pains both before and after weaning.
I remember reading Adventures in Tandem Nursing, which *everyone* who is pregnant and nursing should read. One lady in the book was nursing a two-year-old and she developed very sharp pains while nursing. It turns out the little girl was nursing even though the milk had dried up *completely.* She really didn't want to wean. It was a hard time for both of them, but they got through it! Not sure if the sharp pains are more common during pregnancy with breastfeeding or if that was just my personal experience.