I have been getting pain in my one breast it feels like a sharp stabbing pain behind my nipple. I also get sore swollen breasts 12 days b4 my period.

Cyclical breast pain. Is common and can be normal related to the changes in hormones. However the pain behind your nipple could be a cyst or inflammation of a duct, possibly even an infection though that is less likely. Go have your breasts examined to determine what is going on. .