A strange occurrence for the first time.

So this morning at around 12o'clock I decided to try and take a nap since I did not get any sleep the night before. I was pretty tired and out of it lol, as I was laying there for a few minutes I could start to "fall" into a dream even know my body was fully conscious and I could still somewhat move and feel the bed I was laying on. Anyone's opinion on what this is or what occurred would be great, thanks :D

i get a feeling that i am falling in my sleep but then i wake up because of that. I have never felt falling and realizing i am not at the same time.