SORE BOOBS HELP I'M WORRIED

So, hey. My nipples are killing me. Idk why. My brain is making me think that I am pregnant, but that is kind of impossible since the last time I got intimate we just grinded (he did not go inside me and he did not ejaculate near me) and after that I got my period. Help? I just want to sleep well

I am recovering from a week long episode of flu and also started college doing two careers and working. Can that have something to do with this????