It knocked on my window!

Well,this happened to me when I was about eight years old.My friend Caroline and me was having a sleepover.We didn't go to bed until like,1:30 in the morning and I was really tired.Well,we had just turned all the lights out and stuff when I heard a knocking sound at my window like three times....slow steady knocks.I jumped up,turned the lights,and asked Caroline if she heard that,fearing it might just be my imagination.She said yes,sounding really scared.We went to go get my parents and my dad walked all the way around the house with a flashlight outside.He said nothing was there.Then,he went to go get some tea when he heard a knock on the door.He went to go see who it was and nobody was there.He turned on the flashlight and said,"Somebody's definetly there."I was really freaked out. Then,like two years later in the summer,I was up really late one night watching t.v.I heard a knock at the door right beside me.I thought it was the cat,but the knock was up really high.My dad was at the store so I just laid behind the couch until he got back.Then,about an hour later,I was just watching t.v. again when I heard a really loud knock on the window.I ran in the room with my dad and fell asleep there.Sometimes,late at night,I hear things. Remember,I'm very young,so these things scare me.

it freaks me out when I'm alone.