HER 2 + bi-lateral masectomy

I had HER 2 + bc with bi-lat. I had my surgery plus reconstruction May of 2020. I had fat graphting twice, the last one being December 3, 2020. I now have a pain in my back right below my shoulder blade. It's not a muscle pain so I wonder if I should be concerned about it or if anyone else has experienced the same thing. I could just be paranoid in thinking the cancer is back.