I'm too old to answer this from the perspective of being a teenage mum, because things were a lot different when I was a young teenager.
But, my daughter is almost 10 and I will answer this from the perspective of a parent.
If in the future my daughter got pregnant (unplanned) then I would discuss her options with her, and help her to decide what to do. She will know that there is nothing she can't tell me by that stage. We have a very open communicative relationship already, and hopefully that can only improve (despite the inevitable strops and tantrums - and that's just from me!
) ..
Seriously though, I would get her all the information she needed to make her choice, and depending on her age, I would give her my opinion on the situation, then we would work out what to do together as a family. Although to be honest, I can't even bear to think of how her dad would feel if she got PG .. especially before she's 16 ... But, I would have to give him a severe talking to first, and tell him to get over his shock and support her.
I think it's easier in a lot of ways for mothers to accept that their daughter will be a woman one day, but for fathers it's a whole different ball game. Most of my friends are the same. The mum is ok with periods and growing up and stuff, but the dads are having a fit at the length of the skirts, the idea of tampons, and boyfriends are just a complete NONO!
So, yeah, I would hope it didn't happen to either of my kids unplanned... we all want the best for our kids and that means no surprise pregnancies, but at the same time, it doesn't have to be the end of the world if it does happen.