Its easy to get caught up and end up having sex, especially for younger people. Sometimes young people don't realise what they are doing or getting into whether its sex or really anything that good or bad. Its not that they meant to do any harm, its that they did it on accident or quasi-accident. Tough to explain.
If my daughter asked for it I would have to let her since I think it will always be ultimately her decision. I think its healthier to allow girls to have access to birth control so that they don't have to take potentially more harmful measures. I would rather let my daughter have some form of birth control so that she wouldn't get a hold of a morning after pill or worse, get an abortion. btw, I'm not saying that i'm for or against abortion and yes I do know that there is controversy about whether the morning after pill is abortion or not.