Ok, first of all, nothing can take over your body during the phase.  Secondly... OOBEs, astral projection and lucid dreaming are the same phenomenon - the phase state!!
The experience is an illusory one, albeit one that can tell you a lot about yourself and perhaps provide you with great insight into the nature of reality.  So far, in my journey, I have not encountered nor been possessed by anything that I would deem to be a spirit or a demon.  Scary figures in lucid dreams can easily be transmuted into something else and they have shown themselves to be nothing more than aspects of my subconscious mind when addressed diplomatically and with courage.
If anything, experience in the phase has taught me that the ideas conveyed in esoteric cosmology such as spiritual planes and discarnate beings are based on biased interpretations, exaggerations and dogmatic tripe with no firm foundations whatsoever.  You might as well believe in Santa Claus because some kid said he saw him when he woke up in the night to use the toilet.  
Even the idea that déjà vu is a supernatural symptom is a perfect example of many people revelling in unfounded beliefs just because they sound cool - not to mention some silly conspiracy theories out there!!  I'm just going to put a stop to all of this because it has gone far enough...
Just a few nights ago I entered the phase and did a lot of flying.  Then I partially lost lucidity when I decided to fly on a space shuttle with my wife as a co-pilot.  Lucidity would come full bloom when I nearly crashed into buildings only to lose some of my mental faculties all over again.  It was like I'd get lost in the thrill of the experience but still retain lucidity even if it was minimal.  What I didn't realise, however, and I'll get to the point I'm trying to make here, is that I was in some sort of experiential loop whereby I would take off into the sky only to take off again from the ground a moment later.
Now, I only realised I had done this upon awakening... not while it was occurring.  Taking this into consideration, one can see how easily a déjà vu experience could come about in the waking state when a brain glitch occurs making one glimpse preconscious information before it reaches full consciousness.  The sensation, however, is often seen as mystical or supernatural and often associated with precognition.
destinii, on your sting mark, it is possible that you might have done that yourself during sleep but in the phase it was interpreted as being caused by something else.  this interpretation, however, is hallucinatory in nature and not real.  Sometimes dramatic physical changes do occur as a result of altered states of consciousness (lucid dreaming included), but it is rare.  There is a report of someone being hypnotised and made to believe that he was holding a hot piece of metal when it was cold.  A burn mark appeared.  these are nothing but extreme cases of how the mind can affect the body.
In the end, we are nothing but interactive cells.  Our organism formed from these as they multiplied and kick-started a chain reaction.  This impetus will come to an end as do all things.  There is no reason to believe that consciousness in living beings is a ghost inside a physical mass - as much as Jeff up there likes to think it is.  There is more evidence, and undeniably more so lately, that consciousness results from complex matter interactions.  Just like objects in space collapse under the force of gravity (and the more massive the stronger this force becomes), so does consciousness arise and evolve as those cells multiply and the connections become ever more numerous.
Your baby is safe, have no fear.  Why not enter the phase and have fun.  Try to see what your baby will look like in the phase when he/she is born! 

THE PHASE = waking consciousness during sleep hybridisation at 40Hz of brainwave activity conducive to lucid dreaming and autoscopy.