I think my boyfriend is cheating on me!?

I moved away about a month ago to a school about an hour away. So I don't really think my boyfriend and I have a long distance relationship, since we are still in the same area code. For the first couple of weeks he called me everyday and saw me on Saturdays and we texted each other endlessly. But lately, he acts like he doesn't want me to talk to him. He rarely calls me and when I call him he says he'll call back but he never does. Plus, he never answers my texts or IMs. One of my friends said they see him with this cheerleader girl who I know was always trying to come between us. Does this mean he's cheating?