Can someone please help?

There's this guy from my school that i started talking to online and the last time we talked was last thursday. Whenever he signs on he usually IMs me first but he hasn't signed on since last Thursday (Thanksgiving). I'm so confused or maybe i'm looking too much into this? The last convo we had had went pretty well. And he thinks I'm pretty but since he hasn't signed on I'm not sure if he's interested? What do you guys think? plus his brother is usually on so i'm sure that if he wanted to sign on he would.