I think my boyfriend is cheating, do you think I'm right?

I'm supposed to be moving into my boyfriends house real soon, but while the house is being redecorated he comes and stays over at mine almost every night. Well tonight all of a sudden he told me he 'cba' to come and that he wants to be on his own because we had a bad night last night. (We had a bad argument). This didn't even make sense to me. I just got a bad feeling so I decided to go to his and he wasn't even there. I waited about 2 hours and he didn't come back. One minute his phone was on while I was on my way there and when I was half way there his phone went off and he wasn't there when I got there. His cousin just said he had asked him to meet him but that was a couple hours ago and he's not with him ATM unless he's waiting to meet up with him somewhere. I really think he's cheating and it's sad because we have a 4month old baby. Do you think I'm right? Should I end our relationship?