So, yesterday I read through The Big Long Young Adult Pregnancy Post over at Bree Ervin's Think Banned Thoughts blog. It's worth a read, if you can spare the time and the emotional investment. All I know is that I read it (and this isn't the first time something like this has happened), and my first reaction is that is that I should include a character like that in my own story, and ignore the usual stereotypes.
I'm not saying I will, mind you. The project that a teen pregnancy would best fit into is already a bit tied up in ostentatiously ignoring a completely different stereotype. Still, the temptation is there... and I have other projects.
So... we'll see. In the meantime, there's a look at some common tropes that you could alter, invert, or subvert in some very interesting ways.