I've never heard of this movie that has a pregnancy pact but from the sound of it, it sounds pretty odd. I'd say it's dumb if the teenage girls are clearly unfit to be parents or haven't a clue what to do other than caress the baby, which is really the easiest part of it. Assuming they have the finances, ideally some experience with children and assistance from someone else who already has had children and who was/is a fit parent, then I'd say it's not really a dumb idea. I'm opposed to it in the sense that it can take quite a lot of effort out of the girls when as much of that energy should be devoted to school but if they have considered that and do have an alternative around that, such as a GED, then I'm more lenient.
Oh, and
OP, could you make the title of the thread more informative, such as what it's about rather than "stupidstupidstupid!"?