I'm glad that he's not a lazy git in all areas of his life. But as you say, being nice to your parents ( chatting politely to them a few times a year ) does make up for him treating you like a slave 365 days.
And I see that by " support" you mostly mean " he doesn't stop me doing what I want in my spare time " , rather than stuff he actually does.
But he's not a wonderful father if he won't clean up the kitchen , because his child or his pregnant wife might get ill. Or wash the dishes so they can eat off clean plates.
I see you have tried talking to him and it has made no difference . His reaction is to say " I'll do it when I want to , not when it needs done " . Which is is the same as saying " it's not my responsibility , housework is beneath me , I'll leave it until the slave does it " .
So if talking hasn't worked, you will neee to take action. All I can suggest is that you stop doing all areas of housework and wifework that affect him. And never do anything that is HIS responsibility.
I realise you can't do anything about his avoiding his share of childcare, in that you cant just leave your toddler unsupervised .
So if he doesn't wash the dishes and clear up, don't do it. And don't cook for him either. Personally I'd just make soup and a sandwich for myself and toddler. Or I'd have a large meal at lunchtime at work and just make myself and toddler a snack.
If he asks where dinner is , say " I want to do it when I feel like it, not when you are ordering me to . Why are you such a nag? "
Or " there wasn't enough space on the worktop because of last nights dishes " .
Or " I assumed you didn't want dinner as you didn't wash the dishes " .
Stop doing all his washing and wait until you feel like doing it. Or start and then decide to sit down a watch TV in the middle .
Don't do any wifework , like cards or presents for any of his family . He needs to do it when he feels like it.
This is REALLY TOUGH because you have to put up with your house being a mess. And it feels petty to put washing in the machine and leav his lying in the basket .
It it's not nearly as petty as a grown man saying " I'll do the dishes when I say so and not when you say so. "
But you have tried words and they are not working. And you onlyhave a few months before baby is here and you will have no time to deal with a spoilt lazy teenager .