Sore breast..

Would anyone know why only one of my boobs hurt? It isn’t like a nipple pain or any kinda pain I’ve felt before it just kinda hurts. I don’t have a lump or anything that me or my SO can feel .. but should I go see a doctor? It’s the right one which is slightly smaller than the left. I’ve heard it can be because of hormones or something like that. But has anyone else experienced this if so did it go away?