Boob one size bigger then the other

I had someone comment how my boobs were almost one cup size bigger than the other. I had a baby in January, I did not breastfeed but my right looks like it’s one cup size bigger than the left. I’ve always had one slightly bigger but now it’s a huge difference. Someone even said it could be a symptom of breast cancer. I’ve made a dr appointment because I’m not frightened but was wondering if anyone else had this after pregnancy