I found several red scratch like lines on outerside of my left breast

I'm 23 yeas old unmarried.

Today after bathing in shower I had a mild pain on my left breast. When I noticed it , I found several (10 to 11) red scratch like lines on outerside of my left breast all reaching towards areola. They are not straight lines . But converging on way. They are not stretch marks as I have some stretch marks I was able to identify that it is not stretch marks.

If not stretch marks , what are those thin red lines on my breast that cause me mild pain. ?

Without a pic its impossible to say for sure. They could be spider veins ie fine varicose veins or if you are convinced they are the cause of pain they they could be the sign of a breast infection.   Go see your doctor.