What Causes Sore Breast And Nipples Along With Cramping And Headaches?

My husband and I are trying to conceive and I am 3 days before my period is due. I am experiencing sore breasts and nipples for the past few days now with each day getting worse. I also have had cramping over the last weekend and headaches that started yesterday. I have been having to use the restroom every 1-2 hours which is highly unusual for me and even have to get up throughout the night. I took a pregnancy test this morning and it was negative but wondering if it could be from having to use the restroom so often?