What Causes Sore Of Breast?

HHi am 37 years old. My breast have been sore for three days. I had my cycle two weeks ago. My husband had a vvesctomy12 years ago. The right one was really sore for two days early in the week but it we away. So.what does this mean. They hurt when I move or when I touch.them the only otherer time they have felt like this ever is when I started nursing