I have been very sore on my right breast on the outer side(toward my armpit) for about a week now. When I get full of milk it is worse and when I empty it I can feel some lumps. I cannot seem to get the lumps to break up through massage and/or heat. I went to my GP today and she want to send me for an ultrasound.

Any thoughts on what this could be and how I could maybe get it to go away? Also LO is still eating off that side and I haven't noticed a drop in supply.