I, too, have had pain quite similar to yours. I have a hx of br ca on left. Had needle biop on rt 1 yr ago. Have had from brown to dark green discharge on right for 3 yrs. Now this pain, very sharp and continual, goes from 2 oclock position to nipple area, then makes a "C" shape from side of breast up to armpit. It was so bad, that even my neck gland felt swollen and hard to swallow. Being "self-pay", has made getting into drs AND getting tests done, a slow procedure. In the meantime, I am mentally drained, with my history, extreme family history of breast ca, I am reaching out impossibly, I guess, to the stars to get some sort of answer on what is causing this. Good luck to you, if you find out what causes yours, please write back.
Since there are no specific breast symptoms the pain you describe could be a referred pain from another area of the body .... cervical spine comes to mind. You might have some sort of imaging done involving the neck and shoulder area if this pain doesn't go away soon. Seeing someone at a Pain Clinic might also be helpful in finding out exactly what's going on as well as some solution to the pain. Regards .....