I Had Surgery For Precancerous In My Right Breast. It

I had surgery for precancerous in my right breast. It healed good. But now my right arm from my elbow to my shoulder and under my arm pit and right breast has been swelling and hurting. It is getting worse. My cancer doctor keep saying it nothing she did. My family doctor said he can't find nothing. Can you please help. I had the er tell me it is Cancer but my cancer doctor said it is nothing she did.