Obsessed with cheating posts or real suspiction?

I'm due on a couple of weeks (#2) and my SO and I are a happy couple with ups and downs but with a strong relationship. I don't know if I'm being influenced by so many posts about husbands cheating during pregnancy (or not)... please let me know your opinion: you know that when you open Facebook it offers you the last pictures taken in case you want to post them. Well, today my SO opened FB in the couch next to me just naturally as he  always does and I just saw a nice picture of his face in B&W that he hasn't show me or put as profile picture in any of his social networks that I know... I just asked "And this nice picture of yours?" He just answered: "Just my ugly face, I was trying my phone new filters". Am I having the wrong feeling thinking I wasn't supposed to see that picture that he might be using with a purpose I wouldn't like if I knew? Thanks for commenting!!