Re: Was your gut ever wrong about cheating?
Unfortunately for me, no. But I didn't understand my gut. I knew I was jealous of this other woman, but she lived in Chicago and I have friends of another gender, why can't he?! Unfortunately, once I found out something untoward was going on, every time I suspected something more, later I would find out it was true. I'm sure it is different for every person, but for me my "6th sense" has (sadly) been right every time.
I think you should really inspect your gut feeling and where it is coming from. Then (especially if you think you are missing a chunk of the picture) investigate. I hate that that that is the only way to know, because it will tear you up inside, but the shame of cheating combined with the possibility of losing you (if he wants to stay--he won't admit to it) will make the cover-up a good one if it continues.