Hey, everybody. I need an advice and an opinion on what might have went wrong.

I started seeing this girl couple of weeks ago. I couldnt see her very often as I am often busy with work and she is busy with school.
We went on 3 dates and everything was going smoothly. By the end of a third date (we went rock climbing) she invites me to go to a club the next day. I say yes. I drive her home, we make out in the car (she lives with her parents), saying see ya next day. The next day at about 4pm she calls me and cancels saying that she needs to stay at home. That was last saturday. On tuesday i call her to ask her out for wednesday, she says she "would love to" but will know if she can come out in the morning. At 12 she sends me a msg through facebook saying that her phone got broken and she cannot make it. I say fine, call/msg me next time. Me and my friends were planning a bbq get togather on friday, so i decided to invite her. I send her a msg on facebook (tried calling her but in goes straight to voicemail, indicating the phone is off). Now i am not getting any reply. What happened? Is it too early to worry?
What should i do?

Thanks in advance.

Best case scenario, she's playing hard to get. It sounds like something went wrong at the makeout session, like maybe she thought you were just friends and now she's freaked out because maybe she's seeing someone she didn't tell you about. Hard to say. You can keep inviting her out, but I think you've done enough work and been flaked out on enough. Maybe ignore her for a week, then try again, hopefully she'll come to you by then. Oh, and the typical advice, go out and bang 15 girls and you won't feel so bad, blah blah.

Worst case scenario is that she's dating another guy as well and is waiting to see how things pan out. Move on and check in with here later but don't cling on to her at this point because she's not willing to build something.