I get dull pain under armpit connecting to breast in left side also with pain in upper back of only left side. These happens before my periods 1 and half week like almost 10days. I had kept note of it. Previously 1 and half year back I had stabbing pain in left breast with back pain had got the mammograms done at 2 hospitals they said nothing is there and got Vitamin E tablets to take. Still experiencing the pain now after a year I have stopped taking the Vitamin E tablets a year before.