HELP? what is this

Ka
Has anyone expierenced really HEAVY and very sore breasts??? I'm now having pain of the left side of my breast, no lumps, just very VERY tender to touch. They have never hurt like this, I don't get breast soreness ever, even while PMSing OR when on my period...
Yes I have been sexually active on my fertile days / ovulation. Please help me??? Could this mean pregnancy??? Who expierenced this???