It is possible that there are an infinite number of parallel universes but on one really knows for sure. If space and time continue to bend the way astrophysicists describe, there is no end to the possibilities for parallel universes. It is important that we keep studying the universe, so we can more fully understand, although complete understanding is probably not possible.
I believe some things will always remain a mystery. Parallel universes are one of the many paradoxes in the universe, in which the more we know the more questions we have. The universe is limitless and so are the possibilities.