Could he be cheating or something?

Okay so for a while now I'm gonna say right before I had my son or when I did (3months ago) my husband started being sketchy with his phone. I usually leave my phone anywhere cause I don't care I'm not hiding anything I barely have friends as well so I let him use it when he wants to or whatever. Well he's been acting weird he could be charging his phone and if I go near it not to grab it but simply sit next to the area his phones in he rushes to grab it and takes it with him. At first I was like okay maybe he's acting like this cause he wants privacy even though I've never been the type to go through his phone I'm just not into doing that I should always feel like I trust him. Well three days ago I went to charge my phone and his was charging so I removed his and put mines in and then I jokingly said "someone texted you" and he quickly got off the couch ran to me and asked who and I showed the screen and I said no one in just kidding he starts raising his voice kind of upset "give me my fucking phone" and so I'm like whoa relax and he grabs mine and I'm like "I don't care I'm not hiding a single thing" then he comes from behind trying to grab it and I'm laughing cause he kind of tickled me and then at some point I manage to get up and he pins me like the cops do when they Want to arrest someone but he kept pulling my arm from behind upwards and I was in so much pain I screamed and asked him to let me go about five times and I teared up threw the phone and when he let go I asked why do you think it's okay to hurt me and when he responded he said "cause I know that's how I'll get what I want" I didn't say a thing back. Two days later I start feeling very bad about this so I ask him straight out if he was hiding anything he said no and I'm like tell me I'd rather hear it from you then find out alone. He says no and then I'm like why won't you tell me the truth and he says "because I love you" and my heart drops cause I mean why else would he say that. And then he just says one of my exs texted me and it was just a hi bye and she asked if I was a dad already and I didn't respond so I'm like okay and then I asked for her full name he gets mad and starts yelling "why the fuck do you want her name" and I struggled but I got the name out of him I checked her profile and well he likes all her picture and posts. I dont freak out I say nothing to him I didn't want to seem crazy... Then through the night my son wakes up at5 am so I decide to grab his phone and run to the bathroom and I found nothing and he didn't lie about the texts, well when I walk out he's with my phone light looking for his phone and I'm like oh shit and he's like have you seen it and I have it behind me somehow I was slick enough to slip it back to his side and he found it and didn't suspect a thing, mind you he's a heavy sleeper so I don't know how he woke up at 5am just to look for his phone.... Maybe I took too long in the bathroom I don't know. So I'm like what's happening why is he acting aggressive but isn't hiding a thing? My best guess became he deletes things but I don't know and I am so lost on what I should do. My gut feeling is he's hiding something.. Not necessarily sleeping with someone but maybe talking to a girl or something. He also never answers phone numbers around me unless it's in his contacts. Any ideas??