My odd dreams

Ok I'm a noob so I'm not sure if this is the right thread for this as it is about dreams and aliens.

When I was younger (about 11) I used to have really bad nightmares about aliens. The dream was always the same. I would be walking in the street and see a HUGE winged figure fly across the sky pursued by several UFO's.
When I was in midpuberty (about 13) they stopped.

Now I am 17 and have recently had a more sinister dream. I dreamt that I saw a thin hand and fingers attempting to pull my window open (it has a catch to prevent this that can only be opened from the inside). I dreamt I got up and ran to the window and saw a tall grey humanoid running into the dark.
I then ran into my mums room and saw a similar being at the foot of her bed holding some kind of instrument. When I entered it looked at me and disappeared. I looked out of her window and saw it running through the gardens and fences.

I then had an even odder experience because I became aware I wasn't awake and pulled myself to consciousness.

Just needed to get that off my chest and hear if someone had a similar experience.

It could be

A) All of your fears coming together and transformed into aliens in your dreams. I wonder if you read alot of comics with aliens or read about them.

B) You could have had an encounter with one that you have no memory of. Your memory is locked away deep inside of you and can only resurface through dreams.

I have dreampt of aliens two times. One was on a space ship, and another I'm not sure where. The first I can't remember, since it has been so long ago. The second the aliens were harvesting human body parts from half formed clones with transulecent skin, who could feel extreme and intense pain. I wasen't sure if the aliens either didn't care or actually liked it that way. I woke myself up very quickly once I realized I was dreaming.