Mirrored document

You may have already found the cause and fixed it, but if not, there is an Acrobat Preflight Fix-up that will flip the pages to the correct orientation, see attached.

Can you try print to pdf and then make sure that the mirrored output says NO...Maybe this got changed by accident.

File: Save As .pdf (then clicked, best for printing).

What exact steps are you using to generate the pdf?

-Dax

This is a word document, though.  NOT an image.  The entire document is suddenly mirrored when I save it as a pdf.  When I open the original doc in word, it is in it's correct orientation

it is because it was a copy/pasted image and then manually transformed. Right click on the image and save it out. Make sure it is the orientation you want in the saved version and then replace it in the doc. It will fix your issue.