I'll be 37 weeks Wednesday, my boobs have been sensitive all pregnancy and I've been producing…

I'll be 37 weeks Wednesday, my boobs have been sensitive all pregnancy and I've been producing colostrum here and there but here lately my boobs have been super sore and itchy, and I don't even want to wash them or let my husband touch them! But in a bra/shirt they don't bother me, just when I shower and if they get touched or rubbed up against something and they sometimes burn and feel like they're cracking... is it almost time for my milk to come in? I didn't think it came in until after you gave birth? Am I just making more colostrum?