If the universe expanded in a few plank time to a huge size...?

That means that it went faster than the speed of light, which nothing IN our universe can. And Einstein said that there would need to be a infinite mass to go faster than the speed of light. So can we assume that by this the universe is infinite? And if so does that mean if there was multiverse then the big bang would get proven wrong because the universe isn't infinite, therefor it couldn't have expanded so rapidly.