The pain comes and goes. It also hurts and has this uncomfortable feeling. The pain is also sometimes side of my breast, or left side of chest, underneath the arm, along the inside of my arm, my back, sometimes my shoulder. I get worried and stress about it so much that sometimes its hard to tell where exactly I am feeling that pain discomfort. My actual breast does not hurt. The doctor says it the pectorals or muscles around there, possible a strain. Both she and a breast clinic examined me with no swelling or lumps or anything unusual but it continues off and on. Have not been able to tell if anything in particular gets it worse or better. Awaiting results of mamogram but this is a routine first time because of my age. I am 50.