ok...what now?

mate dont sweat it, if you left a message its all good. If you didn't well... stupid you. There could be a milion reasons why she didn't pick up the phone, one thing i wouldn't do is bother thinking about why she didn't. Just remember she still gave you the number and what not, talk to her in class tomorrow.. maybe start off with "hey you able to read my writting?" or something like that.. then she probably bring up the fact she got your message.. and boom your talking... see walk in the park