What Causes Increase In Breast Size And Along With Cramps?

Hi, my beast have been growing and hurting for the past week. I believe my persiod just started today and my cramps are so severe I felt i was dialating. anyway I couldnt pee. I drank a bottle of water and i felt much beter. My breast are still big and my nipples are still gettin hard for no reason. My body is warm uti shiver. Do you know whay i can do?