TMI sore bump on nipple

This happened a couple weeks ago and I had accidentally popped it and pus came out and it went away after a couple days. This one is closer to my nipple and is very sore, so much so I almost can’t stand wearing a bra. I’m 35 weeks pregnant, is this something that happens when your breasts are getting ready for baby? I have an OB appointment tomorrow and plan on asking then too, just thought I’d ask here if any one has experienced this and what I can do to ease the discomfort. Thanks