Yes you can still file your tax return. If you are getting a refund there is no penalty for filing late. If you owe tax due, then get it accomplished and pay as soon as possible--your penalties/interest began after April 15.
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.**