Why am I having these weird nightmares?

For the past few nights I've been dreaming about death. The first one was with me and a couple of my best friends; I was waiting for one of them to come out of a room I don't recall ever seeing before, and then I saw this weird looking person that made me feel frightened hiding so my friend couldn't see them, I was yelling for my friend to leave but they didn't understand. Anyways it ended with the three of us hiding on a bed and a person coming towards us who terrified me, I eventually woke up extremely startled. The second one was about myself; I was at my house alone, I heard two different people trying to break in, they tried to kill me but I ended up killing them; Their bodies didn't go away they stayed wrapped up in blankets in my house in two separate rooms. I proceeded to tell everyone what had happened, but when I told them I knew their names and they were two names that I don't know anyone named. I'm confused, because I don't watch anything gory or scary before I go to sleep.