I can't find any way to access the payment schedule or information regarding payment at all on my account. It says if there is an issue to call the IRS, but that's literally what I payed TurboTax to do
Once you submit your taxes for filing and they are accepted, nothing can be done within TurboTax as your information has been submitted to the taxing agencies.
Please see the link below for additional information as far as when your payment will go through.
There is also a handy reference at the bottom of the following link as well that you can click about what to do after you file your taxes. I recommend clicking on that as well as it provides more direction as to what to do if your payment does not go through as you directed it to.
As long as your payment is scheduled to go through by May 17th, you will be considered filed and paid before the due date.