Sore boobs... has anyone had this happen?

I always get sore boobs (well, sore nipples mostly) a couple days after ovulation and it lasts until AF arrives. Well this month I felt nothing at all after O. Now AF is due today or tomorrow and my boobs are all of a sudden starting to feel heavy and a little sore. I felt a bit of a twinge last night and today the heaviness is more noticeable. DH and I use the pull out method (we are not actively TTC) and I didn’t even think we had sex in my fertile window this month 🤷🏼‍♀️ if I am pregnant it will be a wonderful surprise, but we aren’t planning for it...

Has anyone had this happen and ended up pregnant?

Also, I feel a little crampy but mostly in my lower back as opposed to my front lower abdomen which is where I usually feel AF pains. I’ve been nauseous and tired all week but that is a usual PMS symptom for my anyway.