It has been 3 days for my e-file. Still in pending state. Not sure what's going on. Is e-filing slow nowadays? How can I know if IRS received the file from Turbo Tax?

Pending simply means that your e-filed return is on its way and that the government hasn't accepted or rejected it yet. Until they accept or reject it, they won't have any record of it.

Also, once you've been accepted, wait at least 24 hours before you use the IRS Where's My Refund? site. If you jump the gun, you may be told – incorrectly – that you never filed.

Please click here to check your return status in TurboTax.

Please see, FAQ for more information regarding pending return: https://ttlc.intuit.com/replies/3302106

What happens if it’s still in pending beyond tax deadline?

And can I be assured that IRS has received the efile and there is no technical glitch on turbo tax end where file was never sent to IRS?