Maybe you did not file it. What does it say in your account for 2017? Unless it says "accepted" it was not filed.
Note: If it says “Ready to Mail” or “Printed” that means YOU have to mail it yourself. TurboTax does not mail your tax return for you.
If you did not file it, then print, sign and mail it now.
If you are getting a refund, there is not a penalty for filing past the deadline. If you owe taxes, the interest/penalties will be calculated by the IRS based on how much you owe and when they receive your return and payment. The IRS will bill you for this; it will not be calculated by TurboTax.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**