I'm not sure where you live, but please be careful. If you "manage" to survive on less than you really need, some states will say that is all you need (reasonable support). If you aren't getting enough because he gives you more of the household bills, it is in your best interest to ask for more to cover those bills. Example: if you get 800 for bills and groceries and you are presented with a 600 electric bill you have never paid before that is 3 months overdue, then you send a matter of fact text or email that says "the 600 electric bill was not in the original agreement for me to pay. Please add 200 to the monthly payment to cover that." Then save that message and all responses. Expect monster, do your best not to get upset, and reiterate that he is asking for you to pay more than agreed on.
Your choice, of course, but an MLCer will try to cheat you so they have more money for themselves. JMO. Mine never paid a penny of child support, nor paid for anything for our son (no health insurance, no car insurance, no activities. Nothing).
Also be aware, he never has to file for divorce if he can get by paying only 800 a month. In my state, you'd be getting 500 per child. And spousal support for yourself, which would be considerable. That is 1500 plus spousal support. 800 is a DEAL! I'm not sure of the point of waiting, but it might be your area is best that way, but you are getting short changed as are your kids.