Gut feeling causing worry

Hi Brooke! On Saturday night my fiance and I were out with some friends. While we were all sitting at a table having drinks I saw my fiance delete a text message on his phone. I instantly got this bad feeling and negative thoughts began. He saw that I noticed and to me he looked guilty, but he quickly said “this guy I met through a friend keeps texting me nonstop to meet up and go to business meeting with him, and its annoying.” When we got in the car I asked why he deleted a text and he said “why are you all in my phone?” Because he got defensive, I got even more upset and anxious. I stayed calm and said “it’s just weird you would delete a text, so I am just asking why.” He said again, “I already told you, this guy keeps texting me and I just delete it because it’s nonstop now. I rarely respond to him and he doesn’t get the hint.” I am not one to push the issue, because I know privacy is important and he said it’s nothing so I try to respect that. He also takes his phone privacy serious as he and an his ex used to go through each others phones due to lack of trust and it was the demise of their relationship (from what he’s told me). Yesterday I didn’t think anything of it… and then randomly, out of nowhere, on my way to work today I get this sick feeling in the pit of my stomach. Thoughts like: none of this adds up, why delete a message? Why did he get defensive at first when I asked? (he said its because he was already annoyed with me as we were bickering earlier in the night) I addressed it with him and he responded “I told you what it was, if you don’t believe me I don’t know what to tell you. I can’t control your thoughts.” Obviously I know it is my thoughts causing this feeling but I really can’t shake it. I’m so busy at work, but I can’t stay focused because of my fear that something is going on and that he could be cheating. I want to believe him and let it go and move on, but I still feel that gut reaction of “something is going on,” and I want to know if my gut is right. I really don’t want to be that person that doesn’t trust my partner and is constantly accusing them of something. How can I move past this? I’ve tried to do some thought work but my mind keeps going to “trust that gut feeling.” I really don’t have any other evidence that something is going on, and I also don’t search for anything ie: go through his phone etc.. because that seems extreme.