[tialaramex]

There is no reason to expect any particular number of universes. We've observed exactly one, this one, which had to exist or else we wouldn't be here to observe that it existed.

Our universe is finite, so although it is unbounded (lacks edges) there aren't an infinite number of anything in it, galaxies, stars, M&Ms, grains of sand, atoms of hydrogen all finite.

[atq2119]

Has that really been established? The observable universe is finite, yes, but I wouldn't think that automatically implied that the universe as a whole is.

[pixl97]

Simply put we can't know and we can never know if the universe is flat. Now, if the universe has a curvature then we could use that as a baseline for the size of the universe, but as of so far we've not detected one.