Sore breasts

My breasts have been feeling a bit sore for about a week or more now. Started off with just one breast having a weird feeling but both she been sore. More so after taking off my bra. I’m 12dpo. Today they feel even more sore. They hurt when I get up from laying down (no bra on) possible early pregnancy symptom or just hormone imbalance? My Period is due in two days but i know that’s not gonna happen because I am on BC and I have pills for a few more days. (Missed pills beginning of month)