I once had a friend I had known for half of my life. Once we both graduated from school we started seeing each other less and less and he stopped logging in on any of the IMs or game we would play together. After months of silence I got a call from him, telling me to meet him outside of a movie theater; I showed up at the designated spot about 15 minutes early and waited for about an hour.

I never saw him and I don't know where he called me from because he didn't have a cellphone and he would move around a lot.

It could be that the girl just got tired of you, I don't know. If she doesn't contact you for a long period after this try sending her an email, if you don't get a response or she sounds annoyed just leave her alone and go on with your life.