Boob problems???

So long story short I’ve had this for about a month now and hasn’t started hurting until recently. I have sensitive skin so I assumed it was maybe a soap I was using ( just recently switched) so I stopped using it and it went away after about a week so I assumed no big deal well today I am hurting after I put a sports bra on and I look I have boils now it hurts so bad. I’m 36 weeks and 1 day so I don’t think it has anything to do with pregnancy but at the same time I dont know! I have a doctors appointment tomorrow and I’m gonna ask but wanted to know if anyone has had anything similar! I’ve asked friends, my mother, grandmother and they all say different things like stress, the heat from sweating ( I shower every other day so it may) and a rash.... need opinions and wanna know how to get it to go away 😭