Re: WTF guys.. Girls are Unbelivable. Read this.
First of all, remain calm.
You've sent two texts to her and no answer. Could be lots of things, why assume the negative? She could be away somewhere and her phone went dead, left her phone at home, etc. If she doesn't respond soon, try just forgetting about it and don't send another text or call today. Looks needy, its not very attractive.
Two scenarios: One, somehow she hasn't received/read your message yet and if you keep texting/calling she will eventually see that and it's not going to look good on your part.
Or Two, she, for some RANDOM reason out of the blue, doesn't wish to talk to you right now and the missed calls/texts are going to make you look bad.
Scenario one is most likely. If she hasn't responded by tomorrow night, or you can wait even longer if you want, send her one last text which looks like it was written by an Alpha Male and not an AFC.
"To live is the rarest thing in the world. Most people exist, that is all." - Oscar Wilde