Am I being paranoid?

yo

So my boyfriend and I are still in the early stages of our relationship and have only been dating for three months. We got off to a rocky start but now we seem to be happy. Every week we take one day out of our schedule just to go on a date and spend time together which honestly is what I look forward to throughout the week. Well anyways I dont see him any other days and I fear he may be cheating. I'm not sure if I'm just being insecure and paranoid though because his last relationship ended with his ex cheating on him so I dont think he'd do that to me. First things first, we dont have eachother on social media. I know he has some accounts but we've never bothered adding eachother. Second, hes constantly checking his phone. I mean CONSTANTLY. Last week were at the movies and he checked it during the movie. I didnt think much of it and just figured he was bored or something. Yesterday, while we were...um...well...fucking... I tried,to give a hickey on his neck and he made me stop. I get that he doesn't want his friends making fun of it or something but it raised a red flag for me. Afterwards we layed in his bed for a couple hours watching Netflix all while he continuously checked his phone. Should I be worried? Am I putting too much thought into this??