Why is she suddenly ignoring me?

Been hanging out with this girl for about two months. Been having sex, drinking together, and spending a lot of time together. So, we hung out Tuesday night, had a great time. While we were talking, we both agreed we wanted to keep hanging out. We're currently on an exchange program, and she lives in another area than I live.

We agreed that we'd keep hanging out until we had to go back to our home unis. So the other night I saw her and we agreed to hang out thursday. Thursday rolls around and I asked her what time she wanted to swing by. She says she was going to dinner with her friends, and was sorry she couldnt see me that night.

I didn't bother responding until this morning. I said "no worries, we're going out 2nite you oughta come out.." or something to that effect

No reply. I'm wondering what suddenly changed. Help?

Day2013-05-10T07:22:16Z

It was not even started, so there is no question of ignoring. Forget it.