I had this exact thing happen to me last night. I spent 4 hours crafting an in-depth dog training article, posted it and went to check on my dogs' outside. When I came back in, the page had refreshed by the post was nowhere to be found.
I know better than to not save my work, and generally used Evernote as a backup but in this particular case, it was getting late, I was writing in the Steemit editor and I just didn't do it.
On my phone I have access to the clipboard and I knew I had copied the article previously so I didn't think that it would be a big deal...well the Universe was laughing at me as I realized that I had copied a link to a video I was referencing in the article as a last item and not the article itself and therefore on the laptop had no access to the previous clip.
I have since downloaded several clipboard apps for Windows 10, beaten myself around the head with a wet noodle for forgetting and gotten some sleep...
Lesson Learned!