When you are checking the status, be sure that the filing status matches what's in TurboTax and that the amount you enter at the Where's My Refund? is only the amount for your federal refund and not the combined amount for your state and federal.
This should allow you to then track the federal refund status. If you still cannot see it you, you may wish to call the IRS for additional assistance at 1-800-829-1040.