Our knowledge of physics in the first 10^-44 seconds after the beginning (which, admittedly, is a pretty damn short time) is virtually non-existent. This instant is known as the Planck Time, and since we don't know what happened before the Planck time with anything even remotely resembling certainty, we absolutely don't know what happened before the Big Bang. Regardless, logic dictates that we're left with one of two possibilities:
The universe had some sort of beginning, in which case we're left with the very unsettling problem of what caused the universe in the first place.
The universe has been around forever, in which case there's literally an infinite amount of history, both before and after us.