The version of Turbotax that you install and run on your home computer does not auto-save. When you exit that version, it asks if you want to save the file. Otherwise, you have to initiate a save by clicking on the top line menu File, then Save.
Recent versions of Turbotax create a temporary file when you open a tax return. You might want to look in the Turbotax folder in your Documents folder and see if there is a .tax file whose name begins with a "~" character and then open that file.
