I exclusively breastfeed and I always alternate sides. I don't pump very often. I haven't pumped in over a month. My baby is almost 3 months old, and just for the last few days I've noticed one of my breasts is significantly larger than the other. It seems like the one is filling up and the other one stays soft and smaller. I always alternate sides when feeding, I don't know why this is happening! As if I wasn't already trying to come to terms with my postpartum body, now I've got lopsided boobs 😕