Something knocked back

So I was tapping on my wall because I was bored and I don’t know how to keep my hands busy. But then I suddenly remembered that in some Native American cultures it’s bad to knock on walls or something I can’t quite remember what she said at the moment . But a few minutes after I tapped on the wall by my bed. I heard 3 knocks right next to my head they were crystal clear. I have no idea what to do or what it was but I am petrified.