Best ways to track your flight to see if its ontime?

Hi all,

I'm flying on AA 4749 tonight at 7:30 out of LGA. I tried doing some detective work yesterday to see where it was coming in from. Yesterday it was from PIT on AA 4902. Well flt 4902 is cancelled but 4749 still shows on time. Is there a way to figure out where the flight is originating from before it gets to LGA for my flight? I called AA and they said that information was not available and that FLt 4749 was still "on time"

Any thought would help...preferably before 3PM!!!

not unless you have access to an airlines fleet network computer