I have always said to DH that the reason I want to be a SAHM, besides the fact I want to be home with my children while they grow up, is the fact that I know if I had a full time job I would still be doing everything I do now plus working all day, and I have no desire to double my workload for little recognition.

I think you should just tell DH that you want to be a SAHM after the baby is born because (insert reasons here) and that is just the way it is going to be. Better to plan for it now. But don't tell him that things will be better when the baby is born and you are at home, that you will be able to cook more, have a sparkling house etc, because believe me, in those first weeks after having the baby you will be even less inclined to do housework than you are now, and it will become harder to find the time and the motivation to keep your house spotless when you have a baby, then a toddler running around.