I wouldn't call her. Seed has been planted.
hmmm I must have missed the part where they had sex ..
If thats the case eftda, I wouldn't stress on it ..
maybe in a day or so, call her when you know she is in class and leave a message on her voice mail ....
"I was on my way to the gym and started thinking about you, so I just called to say hi. I'll talk to you soon." and that is it.
it will put the ball back in her court.