Could a black hole actually be either one of two things: a worm hole that leads to another universe or could a black hole be just another universe like for example our universe is within a black hole thats in a different universe??
Like negitron says, it's possible but we cannot know.
As I've said before in several threads, black holes and worm holes produce the same local spacetime curvature. So, to an outside observer, there is no way to tell the difference.