Okay so maybe I'm paranoid but this is what happened:

went to school for a review session, parked my car (Accord Sedan 2003 EX V6) in the parking lot, and then went to class. There were only 30 or so cars in the parking lot. While in class, we hear a car alarm go off. It was making a monotone honking noise (like honk---honk--honk) not that alarm sound that varies (you know with like the honking, then the siren, then the beeping). After an hour, either the person that owned the car returned or the car alarm shut itself off. Now the question I had was could it have been my car and the car alarm just shut itself off? Does the accord 2003 have that monotone honking alarm system and does it shut itself off after let's say an hour? Thanks for your help

 

You can see for yourself what it sounds like by leaving a window open, locking the car, & 'breaking in'. Or maybe use the 'panic' button.

I think most alarms shut themselves off after some period of time. Owner's manual??