I Am 64 And All My Mammograms Have Been Clear

I am 64 and all my mammograms have been clear so far. During the very hot summer I had a white pimple on the end of my nipple which discharged a small tiny amount of creamy colour discharge. This was Aug time and now I still have a white mark where it was. There is no soreness or discharge, lumps or swelling etc, I am still concerned in case something nasty is going on. Please help. Diane.