What are the little numbers on the top left corner of my screen?

[mapwny]

In the top left corner of my screen, there is a small red circle with a number inside (right now it is displaying 12 but last night it said only 3) there is some kind of grey shape behind the red circle. Can anyone tell me what this means?

 

[Papaduck44]

In the top left corner of my screen, there is a small red circle with a number inside (right now it is displaying 12 but last night it said only 3) there is some kind of grey shape behind the red circle. Can anyone tell me what this means?