I doubt it's entirely because of your schedules. Men who want to want to talk bunches to their woman, find time. My guy works 10 to 12 hour work days every day, and I hear from him more than I have heard from any man. He finds time to communicate because it is important to him.
If he's not reaching out, giving him space may work temporarily, but he will almost always go back to whatever is hard wired in him. Also, giving him space without discussing it with him first, and not getting the reaction you want, is going to make you feel more awful.