Before it happens for real

Few times the weirdest thing has happened to me and I don't know if it is the home I live in or if I have suffered from some temporarily hear-hallucination. The few times it has happened it has been in the home.

One time I was resting in the main bedroom when I could suddenly see the bedroom door react the way it normally does when someone enters from the front door and shuts it. I could hear someone's voice and I presumed someone had come home. Then nothing more. Which I thought was a little strange. I went to check. Nobody home. I checked the front door. Locked. I went back to rest, trying to let it go. Then about 5-10 minutes or so (can't really recall) the bedroom door did the same thing and I heard the same voice. This time it was for real. I checked with the person who I had expected to come home and he said no, he had not been there before. I could think it would do with me resting, perhaps half asleep and hearing things that were not real, but my eyes looked at the bedroom door as it was moving (the way it does when someone comes home). It don't make sense to me.

Another time knocking on the front door. I heard and opened. Nobody there. It was a specific way of knocking. Then 5-10 minutes later the same knocking I had heard previously happened again. Opened. This time for real. The person had not been there before to knock.

I'm not on any medications, maybe I should be ; ), but no seriously I'm not delusional (or so I say...kidding, again). My hearings fine. This has only happened a few times, all the other time my hearing is good, or good enough, at least.

Is this paranormal? Is there a glitch in time? Nobody else has heard these sounds (which is scary to me).

What could possible be the reason for this? To make me think I am mad? Why? To scare me?

Just wondering if it has happened to someone else.

PS Previous owners would say would hear a voice that would mimik the voice of family member, only it wasn't so and so. But if that was the case, then how can that "someone" predict what is going to happen 5-10 minutes from then on?