Is it normal for Safari to delete a history item after a quick visit?

I basically searched domain expansion (A fictional ability) on safari and I closed 5 seconds after because I thought of something else. I look at my history, "domain expansion" was on the history. After some time, I looked at my history again and it was gone. The rest of the history today was still there but the "domain expansion" was removed from history. Is it a bug I should ignore or is it because I closed it immediately after I searched?

[Re-Titled by Moderator]

Original Title: One of my safari history deleted by itself today