My LO is 4 months old and until now has breastfed without any major issues. In the last couple of days, though, it's begun to hurt when she nurses on the left side and this morning I noticed blisters which I haven't seen since she was a few weeks old. I haven't changed positions or anything else about how she nurses but I'm wondering if something has changed with her latch. Is that common? She is getting bigger so maybe that is affecting the latch? Or could it be something else? I'm using a gel pad and all purpose nipple cream to soothe the pain in the hopes that this will resolve itself.