Incoming Plane Traffic..Is it a bug?

At JFK I got to the runway, and was told to hold position after asking for takeoff clearance. There were 2 planes coming in to land, so I say to myself, it's understandable that I have to wait. then 2 more came on approach. Then 3 more. Then I see overlapping names in the sky on approach and could not tell how many planes were coming in anymore. It seems like these waves of planes coming in will not stop. Is this a bug or is this normal?