Welcome to HCM. In post partum women severe breast pain during cycles id due to ductal ectasia - when the ducts get blocked due to inflamatory changes some cases its unevacuated milk in a lactating women. Needs to be confirmed with ultrasound scan, that will clearly show if there is any mass lesion, ductal status and inflamatory changes. So after that reatment according to the findings. There is nothing to do with cancer. Good luck.