Black arrow in top of screen

In the top part of me screen, a black arrow appears every 10-20 seconds that goes away when I left-click. It's not causing any problems and it's pretty small, it's just irritating having a black spot appear on my screen every 10-20 seconds.

It also doesn't show up in screenshots.... It looks like a Mac mouse pointer, but pointing up and right (instead of up and left), without a white border, and about 2x smaller.