2001 Chevy Lumina security light ?

i have a 2001 chevy lumina 3.1 liter miles 123400 i have owned the car since 2002 i was driving the car for about a hour i stopped to get dinner when i went to leave the car would not start it had been about 1 hour since i shut it off all lights worked the fuel pump was kicking on the raido worked the one thing i noticed was that the security light was flashing on and off but i never have had a alarm in the car the battery green light was showing also i unhooked the battery to try and reset the start that did not work also pulled the security fuse and that did not work please help . thank you darryl