If you filed your extension electronically using TurboTax, you'll receive emails updating you on the acceptance status with the IRS.
What if you did not file electronically through TurboTax? How do you receive status it was received?
Get a transcript of the Tax Account it will have the payment made with the extension request - https://www.irs.gov/individuals/get-transcript
Since the date has passed for filing a tax return with an extension then whether or not your extension was accepted is a moot point.