Yes, birth control. Most dr would recommend it for helping regulate the raging hormones of a tweenager. I'm not personally advocating it but from life experience that seems to be the norm.
I've asked my wife more than once to give Midol to the 13 year old. She won't for some weird reason so we suffer....
You had sex without protection. What did you expect a plasma TV. (Saw that on fb) If you do find a cure for it you'll make a billion.