That is normal yes. It depends really, how long the vibes will last. At times I have had really rough, intense and prolonged vibrations which have resulted in an OBE, and at other times I have had very mild vibrations and found myself unable to have an OBE. Very occasionally I have felt no vibrations at all and had a really smooth OBE. To be quite honest though, I have had more aborted OBE’s than anything. It takes a lot of nerve and focus during the vibrations to allow yourself to have an OBE, manys a time I myself have become a little frightened and lost my focus, or even given up and woken up because the rhythm or frequency of the vibrations just was not strong enough to cause me to project…I was just lying there buzzing and aware for too long, so I would just give up. Apart from the occasional smooth exit, I have found that the stronger the rushing, crackling force of the vibrations, then this is the best time to try an OBE. Just focus on nothing else but floating up and out. If done well, you will feel the vibrations intensify, grow in force, this feeling can be seriously disconcerting if you allow your attention to wander…try hard to maintain focus, for if you do the rushing will rise to a crescendo and at this peak you will feel yourself float up out of your body, one of the most amazing experiences I will honestly say I have had. Still focus must be maintained. Several times I have wavered when exiting, the head is the last point of detachment with me, and sometimes when losing concentration I have become stuck at the head, half in and half out! Then I have had to give up.
Here is where I can answer your question regarding returning. Again there is nothing to fear, simply wish yourself back and you will be there in an instant. It is well documented that an unbreakable astral cord connects the astral body to the physical, I have never seen this but I have always been able to return to my body without any problems. Although usually due to lack of skill I would return not wanting to! The vibrations are meant to disappear altogether the more you practice OBE’s…I cannot verify this myself as I have not been having OBE’s frequent enough. To be honest I never started out with the intention of having an OBE, I was interested in LD’s and stumbled across OBE’s literally in my sleep! I first experienced sleep paralysis, then another night I got the vibes…this happened several nights, until I got them really strong one night, and fully aware I forced myself out to float up to the ceiling. In later ones I then made myself go through walls etc. There is a clarity or awareness of ones environment when experiencing an OBE that seem higher level than a normal LD. I have had some OBE’s where I knew I was asleep, but by the time I floated out everything seemed so clear and as if I was seeing with open eyes that I really would start to question if I was awake. Even as I floated across my room and hovered perfectly horizontal above the carpet, I was almost convinced I could actually be physically levitating my body across my room! Intense stuff. A real awakening, if you will!
Just as a sidenote, opinion varies widely on the subject of OBE’s. Some say they are just LD’s, all in the mind, others say an actual detachment of mind or spirit or whatever has taken place. I personally say they can be all of these. I believe that during an LD all visual data is constructed internally by imagination, memory etc. However during an OBE I believe consciousness can shift to an external perspective, like a third outside eye. The physics and dynamics of how this actually occurs are beyond me, but I believe this because I have had OBE’s tainted with dream images, where I believe consciousness has not fully shifted to an external perspective and thus internal dream data is mingled with the external awareness, and I have had OBE’s that were seemingly fully external awareness, clear as a bell. Of course I have also had straight LD’s where consciousness is still focused internally and utilizing the imagination and memory to construct the dreamscape we desire. Like I mentioned before I think an OBE is like flipping a coin, or reversing the polarity of consciousness for a period of time. Anyway, just my opinion. Hope it helped.