I could maybe see not calling the police if there was no actual confrontation and you didn't actually draw...for example, let's say it's the middle of the night and two shady looking characters start approaching you across the parking lot. Before they get close you move your hand into position and prepare to draw, and once they see that you're obviously carrying they turn around. In that case no laws were broken and no one was actually threatened, but it's obvious you were a target until they realized you were armed. I don't know if a situation like that would warrant calling the police, but any time I had to draw I would DEFINITELY call.