Thanks for your responses.

It turns out it was probably totally random cause last night he went down at 9pm (later than usual cause of a late arvo nap), fed at 12:30am and then slept through til 7am He's almost never missed the middle of the night feed before so I give up trying to work out what he's up to

You don't really know exactly what it's going to be like until you're actually there doing it.
Hmmmmm yes but Rachel, I want to know now!!! I do agree that he could have picked up on our feelings - DP was probably a bit more stressed without boobies in the house and I was a bit upset when I got back and he hadn't called cause I was literally 5 mins up the road and could have come home to feed and then gone back. I wasn't upset with DS but felt bad for DP that he'd had a rough night so I could have a good night so that could have been enough.

Great advice about daycare too. We do plan to put him in a week or two early (at least, may not have a choice to secure the days I want) and I'll be hanging around as much as he needs in those weeks before I go back to work.