"So where do go from here? I havent said anything as yet. I am in shock not even cried i just feel very calm. Is that normal? "
Do you want to get firm evidence before you do anything like confront him?
I think you need to think about what will happen if your suspicions are proved right. For example would you forgive him in time if that's what he wants or will you just ask him to leave.
IF it were me, and I were sure, I would ask him to leave so that you can have time to work out what you want to do. If he is being unfaithful then he owes you this time and you mustn't let him make this your fault.
Be strong, be definite and be in control.
You say you feel very calm. Are you generally a calm person who likes to assess the situation before moving on?
My guess is that you will either confront him outright or go about getting firm evidence. If you are going away soon could you lie and say your flight/travel plans have been moved to a day early? Leave the house as if you are going away and then come back after a couple of hours to see if you can catch him? Would you feel comfortable laying that kind of a trap, though?
best of lucj=k in what you decide. You sound strong and as you do own the house at least you know you can stay and he can go if that's what you need.