Growing mass awaiting imaging

I have a mammogram and ultrasound scheduled for Wednesday but I’m starting to April. A month and a half ago I noticed a large sudden mass. It feels like a walnut or peach pit but it’s moveable. PCP says dense tissue and confirmed it’s moveable. The mass itself doesn’t feel like it’s larger but my breast seems more swollen. No discoloration, discharge, family history, and dimpling only appears if moving the breast in certain ways. Really hoping it’s just a cyst that needs to be drained. I’m on the IUD so I don’t get a period.