Drinking a lot of coffee can do that. So can an ovarian cyst.
I actually have sore breasts after my period routinely as part of the hormonal shift that is taking place. Good times. Love being a woman . . . ha ha. I didn't know about the coffee anniebrooke! Ido drink coffee. Anyway, I'd mention it to your doctor when you have your next gynecological exam but wouldn't worry about this at this point.
I have the same issues mine starts before my cycle and after but worse in the middle of my cycle my Doctor told me to lay off caffeine and drink a lot more water closer to my cycle and through my cycle to help and it's been working pretty great. Also was told I have a lot of fibrocystic changes during my cycle anyone else?