I was reading through this and thinking to myself "this is pretty shitty" and about to tell you what I would do and then I got to this:
I think if and when we do sleep together again. Condoms are a must.
How long have you known this guy? You say two months and a couple weeks (let's just round up to 3 months). Then he's on a trip for X weeks, that time isn't counted because you weren't around him. Yes, you knew him, but you weren't active in his life or learning more about him.
You then say he needs two weeks away. So that's not time getting to know him either.
So let's say 3 months of getting to know him and 1 month of not being around him during that time. I'm going to assume everything else happened within a months time because I don't see a time reference. So for the sake of convenience let's say you've known this guy for 6 months, 1 month of which, you two weren't hanging out at all.
Why are you having unprotected sex?