Mine are the same and wetting a napkin and heating it up in the micro, and placing it over the nips, works wonders!
That happened to me too, out of nowhere at 22 weeks. It lasted a few days and then the pain was just in my breasts since then. I am 36 weeks now and they still hurt on and off.
It doesn't feel good at all.
How far are u
My nipples were doing that around the same time as you too. It hurt!! Its guessing its just part of the making the milk proccess.