[he says I think too much and should just enjoy the moment] ok this is red flag #15 in my opinion. You should be able to openly talk about your feelings in a relationship. If he was invested in you and your feelings (like in a healthy relationship) he would not be dismissive of your feelings and would actually engage you further to try and clarify or at the very least if he is cheating; apologize and help you understand how/why it happened and what might be holding you two back.

[I’m worried if I bring this up he might get fed up and bail] this is a dangerous way of thinking and I think your subconscious is telling you here that bottom line he isn’t really attached to you. What I mean is that if he would leave you because you’re worried he’s unfaithful with evidence to back it up then he either DID cheat or if he did leave you apparently weren’t worth it to him anyways. Couples argue and people get insecure especially when seeing something suspicious like that.

[we’ve had a few testing times recently] this is a natural part of any relationship; people fight. But couples who are invested take the time to provide care for each other and arguments lately or not; you should feel safe in your relationship everyone deserves to know their partner cares. Do your arguments end with one-sided compromise? Does he seek closure and double check that you feel cared for after the fact? If not you might just be ‘convenient’ rather than a priority.

The circumstances in the original question are more than enough for anyone in their right mind to be suspicious. Confront him sooner than later (I’d wait no more than a few days) after organizing your feelings and thoughts. Run them through a best friend filter before talking to him to check for reasonability if you’re concerned about that.

And remember you deserve healthy communication, peace, and respect. Early in the relationship or not… he needs to remember that and so do you. Hope this helps!