[alot to learn]

I have been separated for 4 years. My ex paid child support at a pretty low level. In the last year he helped make up for it by paying for back to school supplies and boots. I just put the divorce through and thinking it would stay that way kept it at the low child support rate. He has now decided to stop helping out and also let me know he should be paying way more than he does but since it is low on the divorce order it stands. I asked him formally for a income statement and he now refuses. Can I go back to court so soon (3 months) after the divorce and have the child support adjusted?