Weird sensations in good breast

Runnermum

My history:

DX in April 2017 with right breast stage 2b. Found my own lump had 3D mammogram and US. Biopsy confirmed the lump I found was cancer. Because of my extremely dense tissue, my BS ordered a MRI before surgery. 2 more suspicious areas were found and biopsied. A small spot (8mm) came back as cancer so I was multifocal. Had successful lumpectomy and a clean PET scan after surgery as I had 1 positive lymph node. Completed DD AC x 4 & DD Taxol x 4 & 33 radiation treatments. Started Tamoxifen in Jan 2018. Had a 3D mammogram in April with no suspicious findings. Though I do not trust mammos anymore because of my dense tissue. Had oopherectomy in June and switched to Armidex. The past weeks I have experienced weird sensations in my good breast (left) on and off. Have had many breast checks the last month's and no lumps have been felt. Starting to really freak myself out. I am scheduled for a MRI in Oct (because of my dense tissue I will have 1 MRI/year & 1 3D mammo/year, each every 6 months). I would not call these sensations painful but they are more of a tender/sore feeling and occur in 1 area on the outside of breast. Had anyone else experienced anything similar?

Plan on calling my MO tomorrow. 😞