Could my spouse be cheating?

I have been with my SO for 5 years. We have 2 children together. Lately he has been off. He hasn’t initiated sex. Well today we were out, he went in somewhere and I waited in the car. His phone is contacted to our cars Bluetooth and a call connected. Sometimes when we turn Bluetooth off to make a call as soon as someone picks up it turns on again by itself. Well this happened and he disconnected. Later I asked him about this and he quickly denied a call at all and even showed me his call history. Well my mind goes to him deleting the call and now I am paranoid of why he would keep this from me. Also he has been hours late from work every night and says he is just working later.