[Latte]

You can't know if you're pregnant just the day after having sex. It doesn't work like that. Discharge is normal (as long as it isn't really gross smelling... look, use google information healthy discharge, ok, there's a few "it's normal and expected but..." things and I'd clear the air by reading some stuff online). Also, stomach pain could be from anxiety, digestive distress, an impending flu...

The pull out method is a very unreliable birth control method. Don't do this in the future. Even if he pulls out in time, there's a risk of pregnancy via precum, which can contain sperm and has the potential to get all up in there.

Take plan B if you're worried about it. That's effective within 72 hours of intercourse.

Otherwise, just wait until you're period comes. If it's late, wait 2 weeks and take a test.

Also take the pill or another form of birth control so you don't have to worry about this as much.