If you visited anyone's profile yesterday you probably sent a Friend Request without knowing due to a bug with Facebook that just got fixed.
Better check your Activity Log under Friend Requests/Friends Added to see if you recently added or sent friend requests.
I checked and apparently I had four requests sent.
https://www.engadget.com/meta-fixed-a-facebook-bug-that-sent…
FB and most social sites would be wild if search history was revealed