I think it wouldn't be terrible to have kids as a teen - provided you have a supportive family and partner. Of course, I've never tried it for myself, but that's my general sense. If my children have kids young I won't be distraught and will provide as much help as possible - expecting it to be quite a lot for the first 5-10 years.
I imagine that dealing with the feelings of failing society, which has taught us that having children is the worst thing you can do in your life, would be the hardest part. It was still hard to deal with that sentiment when I had my children in my late 30s, even though by that time I had enough life experience to realize that it silly to worry about what other people think. The mind is an interesting thing.
