Today I noticed my left breast is extremely hard. The entire top portion and now it hurts really bad! My nipple is also red and it hurts when DS nurses, but he Is teething so i thought the nipple pain was from that. I've been pumping, massaging etc. I was thinking of going to urgent care but they are closed already. I don't really want to go to the ER if I don't need too. We also have company coming over soon

Any ideas as to what this could be?