Yes, italiah - sounds like you really do need to have a chat with him again - it is hard work looking after 2 children with a 3rd on the way - especially without much support from DH..
It's definitely time for him to compromise hun - both of you wanted this child & these children - not just you. You're in this marriage together..
You're not in the relationship with your kids by yourself - I think he needs to be reminded of these things. Maybe even ask him what it is he thinks you are here for..? Tell him you can't do this on your own & you feel really unhappy about how things are going. Mention how you really appreciate the fact that he works etc but the children & running the household etc is ALOT of work for one person & you would really appreciate the help..
Not sure if this helps but - DH often needs a reminder - I have a big heart to heart - then he says yes - I'll do this - I'll do that.. blah... then things continue on & I realise that nothing much has changed - I raise it again - he then says - I'm busy baby - can you please write it down for me? or remind me? I say - "look I don't want to have to remind you all the time because then I feel like a nag! - I have started to remind him by leaving little notes & saying baby - please don't forget to do the vaccuming..
I have even resorted to leaving a couple of things that he said he would do until he mentions them - then I say - "well.. I did say that I can't do it ALL by myself.. this is a big house you know & i have alot of other things to get done in the day etc etc..." This has actually worked quite well recently - (it's up to you though - you may find it hard to leave things - I struggled not doing the vaccuming ) floor started to look a bit fluffy/grotty but... all he said was - "that's ok - I'll do it - I just need reminding.."