I don't believe in the multiverse as we know it. I don't believe in infinite, alternate worlds certainly existing, but I do know we can mathematically calculate and physically prove the existence of odds, probability and likelihood. I do believe that these "alternate versions of our world/universe" are contained within the likelihood that they may or may not occur. Luck, chance, and fortune cannot be proven. But odds, likelihood, and probability can be calculated. Instead of saying, "I was lucky", ask yourself, "what were the odds"? Replace "multiverse" with "what could have been".

1)Every black hole (essentially the mass) creates new space that didn't exist and is not accessible to us but in there is stored energy from the annihilation of attracted matter. 2) Einstein predicted the existence of white holes which essentially are the other end of a black hole that spew out this energy (from another universe or our own?) but we have yet to observe such an event. We may never confirm it either, because nothing tells us that any white hole could ever essentially penetrate/generate in our universe and space is mind-bogglingy huge for us to catch it and is only getting bigger fast, slipping away from our view. Not to mention that if a white hole created our universe, to have one spewing out energy into our own could be an upheaval. 3) Our universe very much sounds like it started from such a white hole and since a white hole demands the existence of a black one, therefor at least one more universe should exist according to the conservation of energy. Although the Hawking radiation means that part of this stored energy is "lost" albeit very slowly but eventually even the biggest black holes will "evaporate" in some trillions of years. Does that mean that a condition exists where leads to the creation of a white hole and a new universe out of a black hole, or black holes are just dead ends? Unknown/uncertain but here we are, very literally. 4) Quantum mechanics supports the idea that something can be created out of "nothing" athough that requires that the rules of the universe allow for it, which is very super specific in our own universe. This opens up the possibility for other universes to exist but does nothing to explain how these rules/parameters were ever set, to end up with more matter than antimatter. 5) Another theory exists that says that we are living inside a black hole. This could mean that we are quite possibly 3d projections of the information stored in the black hole's event horizon (hinting again at the existence of another universe where the information and energy came from or even still exist at). Surprisingly this theory has produced some verifiable data but we haven't gotten "full on" with it yet. Again it can make sense to me from a physics standpoint, that a black hole creates new space that could end up potentially being a new universe on the other end. Since the routine of our universe is to ever produce stars that will turn into black holes which in turn can help create new galaxies etc, these are a massive amount of dices/chances in a massive/forever amount of time if this process can indeed produce any universe(s) to do so, as long as the probability is not 0. I have to mention though that the creation of this new universe does not mean that life, or matter will ever exist or form there necessarily. So we have hints but not proofs yet and even if we are right for better or worse, we are in a dire position to have to painstakingly collect and cross-verify what evidence we can, go through stacks of theories and ideas..