I've seen A LOT of stigma over it, on here in the few hours I've bothered with this site.
And it's annoying.
No, those that are having sex young will automatically get STDs, STDS DO NOT DISCRIMINATE, PEOPLE DO.
Now that that's out of the way, it feels to me, that it's people trying to stifle hormones and sexuality by association, are part of the reason the US has such a high pregnancy, because these are the people who are not teaching anything, and yet still saying we should not be paying for the effects of abstinence only education.
Guess what people, times have changed people are less inhibited as a society, and yes people are going to screw like bunnies.
So why not educate them so you're not paying for their babies?

Anyway, 13 year olds having sex? What's wrong with it?
As long as they're safe, properly educated and do have a good understanding that sex is not always a dream, what's the problem?
This is coming from a 13 year old.

And your first time is not always special. I'm apathetic towards my virginity. Translation? I just don't give a rat's ass whether I've had sex or not.
And whoever it's with either.
Call me a slut. At least I'm honest.
I've talked to several people over this, not many really cared or wanted it gone ASAP, and only really immature ones, ie. illiterate teens, or ones that really had a good first time thought it should be saved.

Virginity is a social construct, especially since in the olden days, a virgin got way more money than a quote 'used' woman. In other words, women were chattel, who were not allowed to have any sort of sexuality. Do you really want to go back to that for the sake of YOUR morals?
Let's make something clear, your decisions, morals and beliefs are yours. You can't legislate them or force them onto anyone else. So someone who decides to have sex young (who MAY OR MAY NOT BE sexualized early...please don't stereotype here) can choose to do it, what you think is right differs from them and just leave it at that.