Hi. i'm 18, and I have a little black bump in my leg crease right next to my genital area. it just showed up recently about march 2013. I was dating a guy for a year last year and we broke up in june 2012. we were sexually active. but it didnt show up until 9 months later. & i didnt have sex with anyone between that period. i don't believe it is a sexually transmitted disease because of the recent upcoming so i'm just wondering what else it could be.