Filed taxes 2 wks ago; payment date of 04/15; filings were accepted by Fed & State, and the Fed withdrew my payment today but the state IRS has not; should I worry?

As long as you see you filed both Fed and State successfully you are good to go, the Fed and States do not always withdraw on the same day and are different agencies (higher chance of delays on these heavy traffic days). The payment went through successfully for Federal so the information appears valid and the state is just a little behind