everyone loves boobies, big/small, straight/gay.

So.. I'm having an issue. The side of my boob has been really sore and hurting. It feels like a knot but in my boob. And it's slightly swollen feeling. Should I see a doctor? Anything I can do? Or know what this is?... someone help me...
*not pregnant- if I am I'm like 4weeks but I'm pretty sure that's very unrelated.