Birth control and pregnacy is a few things that can cause this. I know with both my kids my nipples hurt so bad. I would go see your dr and see what it could be, just like sandee said pregnancy tests are not 100%
Best of luck
Jamie
There could be any number of reasons and I would just be guessing. I know I have this pain every month when my cycle comes. It could be hormones.
Do not be so quick to dismiss pregnancy as those test are not 100% accurate. Are you on birth control, this can cause the pain as well.
I hope you are feeling better soon and if not please see your doctor and get an answer.