Rebuilding a Relationship

So slightly long story.

I’m currently 29 weeks pregnant and about a month ago I was on my Boyfriends phone, I have his password, he has mine. We’ve never had a trust issue. Well I came across the KIK app. Well I looked in it because it rubbed me the wrong way seeing that app. Well I see that he’s been messaging a girl. It looked as though some messages were deleted from the past. But the messages weren’t talking conversations, they were mostly him sending her dirty pictures. She never sent him any and in the messages he never asked for any.

I confronted him of course after lots of thinking, crying and fighting we decided to work things out. I know he loves me and our baby. But he obviously has some issues to work on. Since finding out we’ve made some progress in the right direction, but when I get to thinking about what he did I always feel so heartbroken. He sent her pictures that he never has me. But he never wanted anything in return from her. I think he did it for an ego boost but it just crushes my self esteem, especially being pregnant.

Ladies, have any tips on helping us move past this and for me to not think about it all the time?