Do you think hes cheating?

He hides his phone screen from time to time, has girls in his insta that have expressed interest in him in the past(when I asked him to delete them he got mad at me for "stalking his social media" and took his sweet ass time doing it), he doesn't think there is anything wrong with chatting up girls from work, we took our dogs to a dog park Halloween party some girl from his work was there because he invited her, I've been finding dog hair in the house that's not our dogs and just found a long as black curly hair in our bathroom (I have natural light red hair). Is this my pregnancy hormones or do I have good reason to be suspicious?