I think he cheated

I have a past with my SO cheating but we put the past behind us and he “changed”! Well today he wasn’t working but he came straight to my house and took a shower which he never do and laid in the bed. He instantly started to go to sleep on the movie which he does after we have sex. He soooo tired but I don’t understand why he so tired. I know people get tired but this is what he use to do when he cheat. I just want to wake him up out his sleep and send him home and just leave him tf alone for good