One thing to add - it appears you have been in the same airspace as a military aircraft but have not heard them on the radios. If they are in fact on with the same controller it may be something as simple as the controller talking with you on VHF and the military traffic on UHF. Some military aircraft only have the capability for UHF comms (although I don't think it is many any more). At my Air Force base, we have military tower controllers who utilize UHF. When being handed of to the civilian controller on departure we are given the option to switch to UHF or VHF. Personally I much prefer switching to VHF once with civilian controllers - I think it gives me much better situational awareness of things going on around me. Hope that helps.