Hi,
I had a uterne polyp removed via hysteroscopy a few years ago, so I sympathise entirely with your worry and the horrible wait for results. Mine was a small one, and I too experienced some bleeding before it was diagnosed after a TV scan.
Try not to worry too much, though I know it is easier said than done. Most polyps are benign.....the vast majority. If the lining looked ok, that too is a very good sign. Gynae doctors are very good at sussing out if something looks normal or abnormal on first sight, and if they thought that either the womb lining or the polyp looked dodgy, I am certain that you would not have a standard wait for results.
Though I am not post menopausal - I am 44 and still having periods, though they are altering a bit, so i think I am approaching perimenopause - I have had multiple ovarian cysts, a uterine polyp and have a fibroid still (which is on the outside of my womb, so couldn't be removed via the hysteroscopy) so I totally understand your concern. I found the wait awful too. I had to wait until my follow up appt after the hysteroscopy, so I had to take heart in 'no news is good news'.
I am sure all will be fine for you too! x