Did you efile, or did you print and file by mail? If you mailed the return, how long has it been?
If you efiled, are you sure your efiled return was accepted? You should double-check with this tool:
https://shop.turbotax.intuit.com/efile/efile_status_lookup.jsp
Did you wait at least 24 hours after acceptance before trying the WMR tool?
When using the IRS WMR tool, verify SSN and filing status are correct.
Look at your actual 2018 return
to get the federal refund amount. Be sure you are using what is displayed on your
1040, Line 20a for the Federal refund amount.
Use only the Federal refund amount. Do
not
use any combined total figure that includes the state refund.
And
if you are paying your fees out of the Federal refund, use the Federal
amount without regard to the fee subtraction; i.e., the amount before
any fees are subtracted.