Dry Spell?

Hi, me and my husband have been married for almost a year and its been great. He's a truck driver and usually works long stressful hours and sometimes can be gone days at a time, which is hard for us to TTC. But my question is, what's the longest you've been with out having sex? It's almost been 3 months and Lord knows I've been the one trying to initiate it, but somehow his "friend" is just too tired to play. I've tried everything but nothing seems to work. Should I be worried?