My biggest hurdle with R

I am 8 months post DDay. My WH has been doing all the right things.. therapy, working on himself, showing remorse and accountability, went no contact with her when I found out….

I just can’t help but keep thinking… but what if it’s all just a front? What if he is somehow still in contact with her, and he’s just learnt to hide it better based off of all the mistakes that got him caught in the first place?

He has stopped working away from home since DDay so I am confident that there is no opportunity for him to still be seeing her, and I have gone through his phone unbeknownst to him plenty of times and found nothing… how are you supposed to get past this element of R? Or does it just come part of the parcel of no longer trusting someone? 😩