What do you mean by "when I turn my 2017 return into a PDF?" What exactly are you doing? Are you using some kind of third-party software that converts other files into PDFs?
"where can I get my 2017 return?"
If you prepared the 2017 return in Online TurboTax, log in and at the Tax Home go to the section "Your Tax Returns & Documents". Expand that section and choose tax year 2017. Look for a link "download/print the PDF."
