15 years post breast reduction - breast pain feels like skin tearing. What could cause this?

I had a reduction 15 years ago with great results. I meant to have a revision to fix some minor skin flaps near my armpits but never did. I recently started having a pain in my left breast near my scar that feels like being snapped with a rubber band or skin tearing. There are no marks on the outside of the breast and it only hurts when the breast moves, not my arm. A compression bra is helping keep the pain at bay until I can see a dr. Any ideas what's going on here?