Moved to InDesign forum
Try Window>Utilities>Background Tasks.
Thank you, so I see the % that it's up to but not which page.
But what happens if it crashes or can't make the pdf file. Will it tell me which page it had a problem with?
No, it won't. That's why I prefer "old style" pdf exporting progress bar. You can re-enable it using nice free script of Marijan Tompa [tomaxxi] - Control Background Export: