Yes its sounds like either Sleep Paralysis or Lucid Dreaming. The best thing to do is, reassure yourself this will end and it won't hurt you. I just started having Lucid dreams the last 2 years and haven't reached the point where I can move my body...so I feel I can't move. A person can also hear and think they see things during both states. Try not to worry and once you realize what's happening it won't seem so frightening.

http://en.wikipedia.org/wiki/Lucid_dream

http://en.wikipedia.org/wiki/Sleep_paralysis