Sore breasts?

For the last few days I’ve had really sore breasts on the sides and under; tender to touch. I worked out like 5 days ago but I doubt it’s from that. It feels worse each day. I’m really scared it pregnancy (only did it with my bf maybe once since my last period and he pulled out and used a condom), or breast cancer (my cousin who’s my age just had it), however I am ovulating so I am considering maybe it’s that? I’ve just never had this before during ovulation. It’s also on both breasts in the same places for each one. Just looking for some insight please!