Na your not weird at all like Brandye said, its probably just your anatomy causing it. A lot of runners get a runners high, yours is just a slightly better kind of high its one more incentive for you to stay in shape!

Lol doc, she asked why it feels good to run not if she should go out and get it on… but hey, she may keep that in mind when she running horny and sees some hot dude

This means you developing sexual feelings - as you should. Depending upon one's specific anatomy, the lips rubbing as you run are stimulating your clitoris. Bicycling is famous for this affect. Any repetitive movement that moves the labia can result in this. There was a major study many years ago about what was happening to women operating treadle sewing machines.

Many otherwise "nice" women were having orgasms at work! And damaging product in the process because they lost control of the fabric going through the machine.

well buddy, just cheer up, u r feeling whats perfectly normal, and u must not feel or thing odd about it. Its just natural!!
well, having sexual pleasure is everybody right but one should decide that when and how. with one's oneself, it would be perfectly ok any time but with a mate, one must choose the proper time and also the proper person.. the one who is worth it!!

Virginity once lost is never regained. Lucky are the people who r proud of the way and the time when they lost it and not the ones who regret it!!

First off you are not weird at all. We all get feelings down there that feel good and make us want to touch and rub it. I started at 12 and it's been going on ever since. It means your body is maturing and you are feeling arousal which is perfectly normal.