No, a teenager is 13-19 Kedar.
Teen pregnancy, huh?!! The example you gave us isn't of teenage pregnancy, I think, more like under-aged pregnancy. Sixteen and up is recognized as teenage, right? ^^;; In any case, I think it's foolish to even consider of it if one hasn't got a stable foundation to maintain and live up to its consequences and responsibilities. The same thing goes for people of all ages. I believe everyone should practice abstinence until their early 30s, and then having married, should consider having children. Till then, they ought to repent for the -divine- sin they will commit.