really weird and scary dream what could it mean?

ok so a few days ago i had a dream were in my house we would all get really scared of something ( i didnt know yet what it was), we would even lock the doors and make sure the windows were closed . after i went to lay on my bed and when i was about to fall asleep i saw a shadow sliding inside of my room opening the door really slow and i was just looking at it i couldnt move and i could barely scream and i was trying so hard to scream for my mom but i just couldnt and the shadow was just standing infront of my bed i guess staring at my while i struggled . then i woke up and i couldnt move my right arm like all of my arm i even grabbed it and let go of it and it just fell like if it didnt work at all i gave up and went to sleep after a few days i told my mom and my brother about the dream and surprisingly my brother had the same dream and also woke up and couldnt feel his arm could this mean something bad? because it really scared me and more when my brother told me he had the same experience i just cant get it off my mind help?