If he hasn't texted me first, is it because he hasn't thought of me?

Doesnt want to annoy you. You text him.

Who knows? It is impolite thing to do.

You don't say how many days it has been. But some people don't really like phones and also some people can't do texts.
Time will tell. If he doesn't text then go out with your friends and socialize so that you do not dwell on this situation.