Why does my left breast still hurt at 7 weeks post op?

I am 7 wks, and my right is wonderful, my left has been the problem all along. it has an ache seems everyday that may last for several hours, and feels like it burns inside at same time. I am 63 yrs old, and wondering if my age has anything to do with healing/ Everyone else doing great...Can the painful side cause pains just underneath my breast in the upper abdomen, and going down under my arm to upper side, as it is on the same side as aching breast..?