Do you think he’s cheating?

I’ve been with boyfriend for 5 years and he just proposed in May. Hes messed up in the past but we moved past that. But I always knew when he was doing something cause I could just feel it in my gut. Well I started feeling that way again and I checked his phone and he had nude photos and videos of himself in his recently deleted that from 2 weeks ago. He took them in the morning before leaving for work while I was sleeping. I confronted him about it and asked if he’s seeing anyone at work or he sent them too. And he said he just took them cause he wanted to send them to me so I had something to wake up to but he just ended up deleting them right away. Which is weird to me cause he’s never done anything like that. It’s hard for me to believe him because of the past. I don’t know what to think