Okay this is going to sound wierd and nobody has to believe me but... I literally travelled to a paralell universe! Not just in the mind or the soul. I was dreaming and I heard wierd siren like calls leading me to a door and I went through and I woke up and I was in a different room in my bed and then I freaked out and went to sleep again and I was in my own bed. It was not a dream it was too real even though I put it in my dream diary. I'm going to do it again.
One can never tell the difference between the dream world and real life whilst dreaming, even when you are lucid dreaming the dream world still seems so real. Then again the definition of reality is a debated topic. All things in my imagination are real, at least to me. They can even alter the way I feel- it doesn't mean it is real on a physical level, or to other people.
In other words I do not think you traveled to a parallel universe.