DATING ADVICE FORUM

I have been dating this guy for the past 3-4 months and we hang out about 2-3 times a week. We have both let each other know we like each other and go on proper dates. He 95% of the time calls when he says he will and texts back usually in proper time. He has met my friends and we have been growing closer. I am all in my head though as he went out of town this long weekend and did not call me for 3 days and I rang him last night with no returned call. I guess I am nervous about it all because I like him and want to move towards boyfriend-ness. We haven’t had a real exclusive talk yet and we say that we are ‘dating’. He is a self proclaimed commitment phobe which I have found out from other conversations unrelated to us. I guess this not calling thing is bringing up insecurities in me about where we are at and where I would like to be. I do not want to pressure him but I also want to make sure he takes us seriously. Also, it hurts that he wouldn’t be really excited about talking to me after so many days. Is he pulling back and taking space because that is what guys do when you get close? I have read 1000 times not to bring up a conversation with him about exclusiveness. What do I do if he doesn’t call? What if he finally does after a long time? Do I say that it would have been nice to hear from him?