Our Universe began from a Big Bang, but that doesn't mean we picture it correctly. Does that mean we, out of all the trillions of galaxies in the Universe, happened to be at the center of the Big Bang? 13.8 billion years ago, the Universe was dominated by radiation, not matter, and when the Universe first formed neutral atoms, that radiation still persists, having been cooled and redshifted due to the expanding Universe. There isn't necessarily a center to the Universe; what we call a "region" of space where the Big Bang occurred could be infinite. There isn't a place where the Universe started expanding because of the Big Bang; there's a time when the Universe began expanding.

Source: Forbes February 11, 2017 15:00 UTC