Underarm tenderness

Hi I am 2 years post bilateral mastectomy for invasive ductal carcinoma in my left breast Her+ and am BRACA 2 positve. Had 3 lymph nodes removed with one testing positive. Had chemo and rads which caused capsular contracture in my left breast. My question is that I am experiencing pain and tenderness when I touch my arm close to my underarm. Do not remember hurting myself and it only hurts to touch but not move my arm. Have an appointment with oncologist on Friday but am just wondering has anyone had a similar experience tia