It's weird..and I think this is one of the flaws of the human mind....we are automatically geared to believe that there is a beginning and end to everything....
That being said....by our logic someone or something would have had to create the "nothingness"...and someone or something would have had to create the thing that created the nothingness...and it goes on forever
Yup that's when you run into the problem of infinite regression. Everything that we as humans know has some type of cause and effect. It could just be that an uncaused cause was the cause of the universe.