What Causes Soreness In The Left Breast?

Hi, I just realized that my left breast is sore. I just had a mammogram and received my results back a few days ago that everything is fine. I am 46 yrs old. I looked at my breast. There is nothing wrong with the nipple but around the areola and on the areola are red lines. Off from the areola towards the other breast is a circled line, not a completely round circle but a circle that connects. Should I be worried?