Is he cheating while working out of town?

My husband works out of town during the week, with 4 other guys he is the only married one (the rest just have live in girl friends). They like to go to bar and grills to eat dinner a few times a week.

There has been times over the last few weeks that he has not answered his phone for hours on end and always has an excuse of why.

He tells me about what all the other guys do while they are out, but he tells me how much he loves me and would never do anything like that to me.

But I cant get this feeling out of my gut that something is going on with him. Help how can I find out??