Was it a brand-new file, never saved in any form--one you had just created, no matter how much time you spent on it? Or a file you'd created before, used, saved, and had just updated in some way, so that you may have lost those updates but not the whole file?
My sense--Mac or not--is that if you've never saved it any any form, then there's nothing to recover.
Suggestion for the future, from one Mac user to another: early on (like in the first couple of minutes) in the development of a spreadsheet, save it to the cloud, either Apple's iCloud or Microsoft's OneDrive (I use the latter for my Office 365 files). That way, it gets saved automatically as you're working on it.
