As jake says, there is no "outside" or "before" or "after". The language we use is not equiped to describe the universe in these terms. If we assume that 4D space-time started at the big bang then the concept of space and time before and after is invalid. It's a thought problem, there is no language to describe it, you have to invent in your own head the necessary thought processes to describe it. I tend to use the "Black Box" technique, ie anything unresovable just gets a label as a Black box and I can then concentrate on thoughts that can be productive.