Double Me?

I am completely, 100% sure that the people in this story were not joking with me. Ok, continue on.

It happened in Spring of 2011. I was seventeen years old and had been caught up with the bad crowd in school. The leader of the pack (let's call her Hannah), suggested that we trespass into a building from the 1800s, and do something to it, such as graffiti or something along those lines. I instantly had a bad feeling in the pit of my stomach, but agreed anyway and tossed all my worries away. The building had been abandoned for years. We climbed the fence and made our way inside with our spray paint cans.

We left our bag of cans and cigarettes on the fourth floor and decided to explore to find a place to smoke and do some graffiti, so all eleven of us set off down the rickety staircase to find a place. I had a creepy feeling in my chest and I was very scared. Suddenly, we heard foot steps following us down the stairs. This scared even Hannah, the "fearless" leader of us. We all stopped walking and listened for a few minutes. None of us made a sound. After we thought they'd stopped, we kept walking. I started to get chills in my arms and legs and the hair on my arms started to stand up straight. We found the perfect spot and stopped there. Hannah suggested that I go fetch the bag three floors up, and I nodded and swallowed my fear. I quietly walked up the stairs without hearing any more noises. I was still getting chills and nearly shivering. When I reached the bag, I grabbed it as soon as I could when I heard the most scary, horrible, terrifying noise I have ever heard. It still scares me to this day to talk about it. It was the scream of a woman, like a blood-curdling, I'm-about-to-be-murdered scream. It sounded like it was right behind me. I immediately was freaked out of my mind so I sped up and started running as fast as I could. Somewhere during the stairs, I tripped and fell down a couple stairs. Me being the weird kid I was, I went to go see what made me trip. What I saw was unbelievable, it was a knife. Like, a bread knife that had been sharpened to its max. I looked at my foot in awe and saw that blood was gushing out of it and that I'd cut my toe deeply. I limped the rest of the way down the stairs. I returned to the group, who were all giving me the cold shoulder. I asked them why and Hannah spoke up.

"You seriously don't remember?" I shook my head. "You just walked by us giving us some type of evil eye and growled at us." She said. I asked her if she was joking as well as the rest of the group and they said no. I explained I had no idea and that it wasn't me at all and that I had been upstairs. I also asked if they had heard the scream or seen the knife on the stairs. They said no. We started to piece things together. I asked them what the "me" looked like. They described exactly what I was wearing and what I look like.

We went to the emergency room for my toe an hour later where I received many stitches. When the doctor asked how it happened, I had no way to explain it and was at a loss of words.

I still have no clarity on this experience and no one I have told has been able to conclude anything. I have no visual or audio evidence, but I wish I did.

I have read that everyone has a double and that when you meet them, you die? I have not returned to the building or anywhere near then since.

I'm just wondering can anyone say anything about this?