Knocking On My Door

So one night I was sitting on my couch and I saw something just slide of my kitchen table on to the ground, I ignored it because things like that tend to happen while I'm home alone. So I continued on watching t.v. And just forgot about it. A few minutes later I hear very loud clear knocking on my front door, so naturally I ran to the door to go answer but nobody was there, thinking that my mind was playing a trick on me I walked away, But only about two steps away from the door the knocking continued clearly on the front door.

So I tried my hardest to just forget about it the rest of the day but as Iw as eating dinner I saw a glimpse of a small girl in a bright white dress running, then it disappeared. I saw that image over and over again through out the rest of the night.

Then it was starting to get dark, My mother told me to go take a shower so I did as I was told and shut the door all the way. As I was showering I heard a faint knock on the door, I ignored it thinking it was someone in my family, Then all of the sudden I hear it again but louder. Yo I yelled "WHAT!" and nobody answered. Then soon it knocked louder and I said you can just come in! But no one answer would keep knocking louder and louder and I would keep responding but nobody would come in or talk. So after my shower I asked everyone in my family if they did it or heard it, They all replied no. I'm confused, I have dealt with these sort of things before but this one seems different, and I should mention every time I see that girl running shes always running outside. Well if you have any ideas please help.