Pregnancy stretch marks.
Mine showed up very late, about late 20's to early 30's weeks along in my pregnancy. They are very small on each side of my torso; where my 'love handles' would be if I had any lol. They are very dark for my skin color, so they're very visible, but I really couldn't care less; I earned them. I was pretty happy though that they showed up so late and are minimal. :)