boobs so sore I cant do anything !

My boobs are literally so sore that I cant hardly sleep. Laying on them is a definite no, moving hurts simply because they brush against my tshirt, touching them, a bra, literally everything hurts ! It is to the point I am almost in tears. They never really hurt. Rarely they are slightly sore a few days before I start and they hurt beginning of my pregnancy. Saying that I am not supposed to start til the 21st and do not think I am pregnant. Other things that can cause this ?