Sharp pain

Between nursing sessions I have sharp stabbing pains in my breasts. It started in my left breast yesterday then today I've randomly felt it in my right one as well. I don't really feel it when she's nursing, it's really only in between sessions. Not sure what would cause this. I was thinking it might be a yeast infection/thrush, but I was looking in my daughter's mouth and it doesn't look like she has thrush and she has had no problem feeding. I made an appointment with my doctor, but the earliest available appointment was for November 8th.