Do NOT use the inteenimater. (A mod or cheat, or hack whatever you want to call it, that gets your teen sims pregnant. It also lets them have love relationships with adult sims, and for some reason.. the adult sims go to school and get homework as well. I don't know, just what happened for me.)
It messed up my sims 2 game, as where I had to start over. I don't know another way to get them pregnant, exepct male sims, but i don't know if it works for teens.. but that's using boolprop testingcheatsenabled true
. That's a tricky cheat, you have to be carreful how to use it.