Pregnancy signs 3dpo

I feel like I'm going crazy here. Had a early mc the beginning of the month. Just 7 days past AF. Doc gave us the go ahead to try again. Had a surge on my opk and things seemed to be timed well. Noow as I wait for test day my lower back is sore and my boobs are itchy like they were before. Anyone ever had that and been pregnant or is my mind playing tricks on me?