Stereo & Electronics - Car alarm problem

Looked through the car manual, can't find anything explaining what the hell is going on. Lately when I set the car alarm on my Camaro with the remote (door lock) I get the 2 little chirps from the horn as usual, then about 5 seconds later I get 2 full blasts from the horn like the alarm is going off. This just started happening out of the blue and it's getting annoying. Any suggestions?

Does it go off randomly? Like just out of the blue and no one is around it?

No, just when I set the alarm. I get the 2 little chirps, and then a few seconds later I get 2 full blasts from the horn and that's it.