Why is my left boob hurting so much?

I'm 19F, will be 20 soon. It's been 2 days and my left boob is just hurting so much, it's sharp & continuous, I wonder what could be the reason and before you say no I'm not on my periods but soon maybe. I've had this pain before too but it was never so strong and sharp, it was random but now it's just for 24 hours.

If any women here been through same, I'd like to know the reason & how to cope it, Thanks.

I will go to a doctor if it won't improve.