It sounds to me like you are still in love with him?
If he's stupid enough to have unprotected sex, he's risking a hell of a lot more than just getting someone pregnant! ( his life! )
tell him THAT!
Did you also warn him about H.I.V?
Good for you. Glad to hear it!
Do you often feel like you need to manage other people's lives? You don't have to convince anyone of anything. Say your piece and let it go.
Which in turn sounds fair.
He'll probably have to learn the hard way.