Yes, as Fani said, If you two agree to be faithful, and you show each other trust all shall be fine! Don't pester him while he is away, though, be respectful and he should treat you with respect right back! =) xo best of luck. Don't worry too much, girl.
I don't think you should worry, honey! Trust him, and don't give him a reason to think that you might not. I think he'll appreciate your faith in him!If he comes back and realizes you're suspicious or fishing for clues, I think he might find that very hurtful. If he's a good guy he won't mess around!
Worrying is natural, it shows you care. Tell him that you are expecting him to have a good time and that you can't wait to share his experiences. Tell him that you trust him. If these are true he should understand and remember he has you to come back to. Also don't forget, he might be worried about YOU leaving you behind as well. Don't forget you have power too but as a couple you should be equal.