Sore boobs/negative test/period late by 3 days

My boobs have been kinda hurting and it is worrying me because I don’t want to be pregnant right now, even tho I only had sex once this past month/cycle and we tried to be safe. My period has been irregular the last couple of months so I don’t know if my boobs kinda hurting may be bc my hormones are out of whack? Not certain but I’d like some peace of mind if anyone can give me some. I’m freaking out.