Lost source file

I am usually really careful about saving files and have just realised that a .story file I worked on for 2 days in November is now reverting to a September iteration.  I have the published output from Nov, but can't locate the latest version of the source file  I worked on in November.  I have read all the information about the impossibility of recovering source files from the output, but I wonder if all the issues that have been experienced with Flash recently are causing other issues? When I opened this file in Storyline this morning (from recents) it was the September version. It is like my November edits never happened (I probably saved 50 times over 2 days I was working on it in Nov).

I have:

 - checked trash

- searched for .story files 

- downloaded recovery software

All reveal nothing.  Has anyone else had a similar experience in the past few weeks? I'm on Windows 8.

Lilian