What to do when she doesn't call?

I met a girl at a party last week and we seemingly hit it off quite well. About halfway through the party, I remembered I promised a friend I’d go with him to the train station to pick up some friends who were coming in for the weekend, so I left the party quite abruptly. When I returned about 2 hours later, I thought I wouldn’t see the girl, but about 10 mins into being there, I bumped into her and we basically picked up where had left off, talking and what not. Well, night goes on and she says she has to catch a bus with her friends but doesn’t know how to get to the stop from the party house. I described a route and then offered my phone number in case she had any difficulty finding the stop from the house. Subsequently we exchanged numbers and everything seemed good. About an hour later, I get a text message from her telling me she found the stop and she had had fun that night. The next night, stupid on my part, I text messaged her at about 1am asking “what are you up to tonight?” Now I realize most people are already out doing their thing at that point in the night. Needless to say she did not respond to that text message. Later the next day, I found a ‘friend request’ from her on facebook.com. After I approved it, I posted on her profile ‘wall,’ saying hey, whats going on, which she didn’t respond to. Another 2 days go by and I decide to call her and see if she wants to get coffee later in the week (that was yesterday). She didn’t answer so I left a message. That brings me to today, when I still have not heard back from her, and am not sure about what to do next, if calling again is a bad idea or what. I think I will call again tomorrow to ask on the spot if she wants to meet up shortly, kind of like a follow-up from the call 2 days previous. Could she have not returned my call expecting that I would call again if I were really interested?

I haven’t been too sharp with girls since breaking up with a girlfriend last Spring so I have tended to overanalyze and dwell on things too long. I can’t think of anything within the past week that would explain why she doesn’t respond to my attempts of contact, when she initially text messaged me first and found me out on facebook.com on her own as well.