What Causes Sudden Soreness And Erect Nipples?

I am 47 years old and my periods are on there way from being irregular. The last week my nipples have been very erect and sore like when I was pregnant. I have 4 sons and I know Im not pregnant. My last baby was 15 years ago. I am concerned because it is there all of a sudden. I have a sister who at 43 diagnoised with breast cancer. It is just so sudden and new.