You really haven't known him very long, and it doesn't sounds as if this is a "relationship."
It sounds as if you've just a had a few nice dates and some great phone convos (and thats great!) But... Did he tell you he was falling in love with you? Did he ask you to wait for him?
I agree, you are young, and unless he has given you some solid reason, you should not wait for him.
I would not worry about him not contacting you, it is probably very difficult for him to communicate with you, or anyone else for that matter, and this does not mean that he is hurt, necessarily. It also does not mean that he's lost interest.
When he comes back, he knows how to reach you. You can rekindle things then. Until that time, go enjoy your life! Maybe some other great guy will ask you out.. and you should go!
Very experienced in dating, older woman advice here (im 30 ok, not old

.. guys will be MUCH more interested/attracted/intrigued by you if you are out there being your own person and enjoying your life and NOT waiting for them. This comes across as needy and desperate. Im not saying that you are, but guys are outwardly frightened of needy, desperate girls.
Try not to think about it too much and Good Luck!