Strange knocks - ghost story

Hello Everyone, This is my first story here and I am sharing it because it happened to me. Some years ago I was left alone in the house and although I have lived there for a long time, it was the first time I had to stay all by myself.
One night just before I slept of I heard the knocks; 3 sharp knocks that sounded so loud to me at that moment. I was fully awake and just lay there I'm bed listening to know if I would hear steps of someone but heard nothing. I felt so scared and couldn't scream and eventually slept of.
Some days later at about the same time, 1am , I heard the knocks again. 3 gentle knocks. But what scared me was that after the knocks and in my petrified state in bed I actually feel the presence of someone come into my room and get in the bed beside me and all of a sudden a feeling of peace and calmness came over me.
I would never forget this incident and have been reading about it and learning new stories of the phenomenon. But I know what I felt and I have a feeling that whatever it was had come to me I'm good intention.
Ghosts and other mythical creatures have been attributes to cause this while some claim it on our brain drifting into such situations on its own. Some call if a death knock. But I still don't have an explanation for this phenomenon. Anyone experienced this please share your story.