New mass?

I had iDC stage 2-3 with + lymph nodes and treated with chemo for 6 months end of 2017. Double mastectomy 1/2018. Then 6 weeks of radiation. I had three fat grafting and then implants 4/2019. I had hysterectomy and I am on an aromotase inhibitor and took Ibrance for 16 months as part of a clinical trial for “early stage breast cancer”. I had cording in my arm after mastectomy off and on but none in say the last year. I have developed pain in my radiated breast. Burning and aching pain similar to what I felt with cording. I have a long thick line of a “mass” across my breast from one side to my nipple. It is like a cord and painful. Oncologist thinks it’s scar tissue. He will order ultrasound but thought it was not worrisome. Has anyone experienced something similar