I haven't received a call from professional monitoring when my sensor was triggered

I was in Home Mode and one of my sensor was triggered. I disarmed my system in a few seconds, and didn't receive a call from monitoring center. I am wondering if this is expected, is it because I disarmed my system that the alarm was canceled? If so, how long will it wait for me to disarm the system? If I would like to be called every time when an alarm triggers, what should I do?