Is he cheating ?..

My boyfriend just stopped talking to me out of no where . Friday morning he left at 10 and I texted him all day and he didn't respond so I figured he was busy at work. And he's been doing this every since then and it's Monday, like we live together and when he does come home he sleeps on the couch and still doesn't talk to me. And I've asked him if he mad at me he won't respond or even text me back and I know he's getting my messages because he's always on his phone. And our anniversary is coming up on the 18th and he being so distant I don't know what to do...