If it has been more than 21 days since your return have been accepted then you
may call the IRS customer service at 1-800-829-1040 to inquire the status of
your tax return.
If it gets to be more than 8 weeks, you can contact the Taxpayer Advocate. https://www.irs.gov/advocate
Please see FAQ (click on see entire answer), for more information about, Why some refunds are taking longer than 21 days: https://ttlc.intuit.com/replies/3302084