You guys aren't planning on slipping away into the "pregnancy protection program" now after seeing that movie are you???...hehe that was a joke btw, a bad one mind you, but hopefully a bit of humor in the situation....
From someone with a very recent personal experience with unplanned pregnancy, my advice to you is just make the best of the situation. I panicked and blamed myself and went into hysterics for days(though my situation was a little different...). No one deserves to go through that, it was not a mistake it was an accident.
And about your mother, you are in college, you are an adult.I am no one to judge your relationhip with her but this is my advice to you, on behalf of your own feelings. Even if it goes against her morals and rules, obviously premarital sex isn't against yours, you should let her know that you expect her to not judge you based on her own morals, that you are an adult. This is where tough love comes in, I know she is your mother, but you should not have to be ashamed just because she is against pre marital sex, you need to let her know that she needs to be there to support you, her child, and put her own feelings aside.
Depending on which route you go I would definitely be willing to give you some advice or even just talk to you a little more privately. Pm me if you would like to talk.