Yanbu unreasonable AT ALL
I have had a similar thing last night (and sorry about to hijack for a rant)
I only realised DH wasn't home at 5am when 4yo dd started crying with a bad dream. DH is currently sleeping on a sofa bed as we have 4 month old DS who is sleeping terribly, so I am up half the night. DH needs to sleep for work, so has completely unbroken nights. I am on my knees with exhaustion, which DH knows.
So I call him, he was at the poker club (not drunk) and says he's coming home. He got in at 5.45am. I have been awake since 5am (not counting the time I was up with DS before that) with both kids in my bed. Got up at 7 and although DH tried to stay up he was acting really strange (hardly surprising given lack of sleep) and so is now in our bed dead to the world.
You know what, no, he doesn't do it much. But he does get a social life (I don't) and he does get to have fun, I don't mind him going out, but to get in so late that is writes off the day is not on at this specific point in time. I should be the one getting the fucking lie in, as should you OP! Pregnancy/small children are small periods of time in life, and it doesn't take much to just calm things down and have a bit of consideration for that short time. I love to go out and party when things are equal, but at the moment they are not.
But the choice is either let him get some sleep, and do the things we planned today on my own with two children (house viewing so he really should be there) or wake him up and have him feel as crappy as someone who has had 3 hours sleep will inevitably feel.
Sorry for hijack OP, rant over, and for all those who say YABU well bully for you for not giving a shit when your partner clearly disregards their well being during times when they need support.