Should I lay cool about staying home alone?

It was the police coming to check on you, not a robber. they have to send a car out to a 911 hang up call. Your address is shown in their dispatch center the moment you call. Don't do this again, as you could have taken an officer away from much more important things he needed to be doing. If anything , the mistake should make you feel SAFER that there is someone there to help you at a moments notice.