Did you e-file your tax return and was it accepted?  

Use this TurboTax website to check the status of an e-filed return and if it was either accepted or rejected - https://turbotax.intuit.com/tax-tools/efile-status-lookup/

If accepted by the IRS use the federal tax refund website to check the refund status - https://www.irs.gov/refunds

After the tax return has been Accepted by the IRS (meaning only that they received the return) it will be in the Processing mode until the tax refund has been Approved and then an Issue Date will be available on the IRS website.

See this IRS website for federal tax refund FAQ's - https://www.irs.gov/refunds/tax-season-refund-frequently-asked-questions

If over 21 days since being Accepted by the IRS and the tax refund is still Processing you can call the IRS and speak with an IRS agent concerning your tax refund.

Call the IRS:  1-800-829-1040  hours 7 AM - 7 PM local time Monday-Friday

When calling the IRS do NOT choose the first option re: "Refund", or it will send you to an automated phone line.  

So after first choosing your language, then do NOT choose Option 1 (refund info).  Choose option 2 for "personal income tax" instead.

Then press 1 for "form, tax history, or payment".   

Then press 3 "for all other questions."

Then press 2 "for all other questions."  

- When it asks you to enter your SSN or EIN to access your account information, don’t enter anything.  

- After it asks twice, you will get another menu.

Then press 2 for personal or individual tax questions.

It should then transfer you to an agent.