My word, this topic hits a nerve...
Please don't beat yourself up over becoming pregnant from a one-night stand. Yes, you shouldve been more careful, yes you were stupid (one night stand, seriously, what about STD's, HIV...etc??), yes, the price you're gonna pay is high... etc... etc...
But, you can't change anything now. And I stand by what I believe: you don't create life. You are granted the privelege of being a part of it, but it is not up to you. God alone decides that. And I have proof. Nothing will stop you from getting pregnant, if God wants to give you a life. And nothing will make you pregnant, if God decides not to.
As for the dad, let him make his choices. He'll be responsible for them one day, not you. You will answer for your decisions, what you made with what you were given.
Your life took an unexpected turn. It can be very confusing, very sad, very frustrating, very lonely. It can also be very exciting, very rewarding and interesting. Allow yourself both sides of the coin.
Mostly, don't bother what anybody says or thinks... not even me. At the end of the day, It's your life. Your choice. Follow your heart. Nobody knows you or your motives or your fears, but you. Please don't listen to others. They/we really don't matter. You do. Yes, you alone. If you're fine, the baby's fine. If you take of you, you'll take care of the baby. It just works that way.