For the past six months my breasts become very sore about a week before my period. In addition, there have been one or two lumps, what I figure are milk ducts or cysts, that are also very sore. My worry is because this month, the pain has become much worse. It has been almost a week of soreness, and I am not due for my period until next week. My question is, should I worry about these lumps at all? (In the past they have gone away as soon as I get my period.) Also, is there any connection between having these pre-mentrual lumps and getting breast cancer later in life? Lastly, could these symptoms be related to the Mirena IUD I have had for three years?