I had that the other day, i slept without a bra an when i woke up my boobs really hurt an kept getting a lil stabbing pain in one of them! Got quite worried but it went away within a few hours an was fine. I didnt have a lift so not sure about the redness on scar but it defo hurt the next morning after not wearing a bra in bed, Im 4 weeks po. Have you had your 6 week check yet? You could always ring the nurse if your worried babe xx