Do you mean first time having sex? I don't know where you'd find stories, but I do know the most common cases in which someone that age would have sex.
Most girls who lose their virginity at that age do regret it when they are older, but you never hear anyone say "Gee, I really wish I had sex at 13!) Most of the time the boy they are with is much older and takes advantage of them, other times it's two 14 year olds who swear they're in love until the day the boy leaves her to go out with her best friend.
My point is, NO ONE, I mean no one, is emotionally/mentally ready to be in a sexual relationship at that age, no matter how mature you think you are.
