Is your husband mature and makes good decisons in general? What kind of job does he have? How long does he stay? Is he obviously intoxicated when he gets home?
I suggest that if you approach this focusing on alcohol related issues and come to a compromise that works for both of you. I suggest that when you tell him he can't he may want to stop at friends house to show you, he's able to make his own decisions.
I worked with nearly all men. I was single. Most of the men were married. We did often go across the street for drinks after work. We were buddies. The men respected me. No passes or inappropriate conversation. I was good friends with several men. I knew some of the wives, been to their houses. The wives trusted their husbands. Some officers did go to each other's houses.
When I worked graveyard, the only places open were on their way home but too far for me.
If you don't know this man, ask to meet him so you can get to know him. Single does not necessarily mean he's chasing women. Perhaps he shares his place with a girlfriend. Meet her, too, so you'll be more apt to know their commitment. Does he have a roommate? Who is in the house when your husband is there?
Perhaps you've had bad experiences with alcohol. If that's the case, I suggest you try to discuss this with your husband keeping an open mind. I agree that doing this every morning is nOT good. You can ompromise by making it lomitted in das aND time. Together, decide how long you're comfortable with him staying.
I suggest that when you say he can't stop at friend's house, he feels like you're taking over his life. He has the right to make decisions for himself. Ideally couples talk together until they can reach an agreement. Controlling spouses make for a difficult marriage.
What does being pregnant have to do with this situation? Yes, your hormones are changing and you're more sensitive. That doesn't mean your husband has to do what you say. You may have difficulty controlling your emotions. You can still have an open non-judgementAL conversation.
You followed him? You're gathering evidence to be angry with him. Why don't you trust him? Why haven't you talked with him about those reasons?
If you attack him in an angry way, he will leave or fight back. You'll have made your situation worse.