Yesterday I Noticed That Left Breast Was Really Sore. I

Yesterday I noticed that left breast was really sore. I went to the mirror and looked at it and its a round spot right under the nipple and is discolored. It also feels like a line of lumps going around the circle and the top. I have made an appt. with my doctor for Wednesday. Do you think this is a concern? My sister is now going through breast cancer and I did have a mammogram back in November 2014. It was normal at that time.