It's hard to say. By experience, I'm inclined to imagine such a thing. At the same time, if it really is possible for universes to exist outside of Paradox Space, which seems likely to me, then those rules that control my universe wouldn't carry over. I think it's reasonable to argue that there would only be one possible flow of time in the absence of time travel. However, there's plenty of science in recent history that points to the existence of multiple worlds that all interact on the level of quantum physics.

[A bit of a pause.]

I've assumed by this point that your culture hasn't developed quantum mechanics or its equivalents.