Alright I've sat next to this girl for a few times in my music class, and recently we exchanged #'s mainly because of the fact that we have to go to 2 concerts for the class before its over. She first brought up the whole concert thing by asking if I had gone to any. Then I suggested that we go to em' together and she said that was a good idea. When we exchanged #'s she said that she would go online and look up the concert times and then call me. But its been a few days and she hasn't called.

Plus last class for the test she didn't sit next to me(might have been bcuz I saw her on campus but didn't recognize her). What should I do next class time when I sit next to her, and what should I do period.

You are rationalizing the situation a bit too much. when a girl tells you she is going to do something she will most probably forget.

You see she gave you too muck push so now she is going to have to do some pulling. Basically she was a bit too nice so now she will have to take it back. It's like 1-1.