No, it's not too late to file a 2017 return. You can still prepare and efile a 2017 return with TurboTax.
There is no penalty for a late Federal return if you are due a Federal refund.
But if you owe Federal taxes, you could have a late filing penalty and a failure-to-pay penalty. So if you owe taxes you should file as soon as you can to stop additional penalties and interest from accruing.