Why can't I receive any text messages anymore?

Suddenly the whole week I haven’t been able to receive any text messages and my friends now think that I have been ignoring them. I have a Samsung SGH-F330 slide phone. I have dropped it many times and it has always worked afterwards. Sometime last week I think I remember dropping it and I can’t remember if I was able to receive messages or not. Its really bugging me not knowing if people sent me something.
Help?