Why does a Black Crow stand outside Above my Doorway?

Ok here is my question, for One I am not Superstitious. The reason I am saying this is because either in the morning, afternoon, or evening when my family and I are leaving to go to work, school or wherever this black crow would be standing right outside right above us not exactly on our roof top but across from our doorway from our duplex. Now the crow never bothered us it was just we would notice him standing there watching us. Some people say that he was protecting us or something like that I am not too sure what it meant. Can someone tell me what they possibly think that resembled about the black crow and all?