with the big bang theory it says that when the universe was created it started to expand and the universe continued to expand so what really stops it from expanding, so it might have an end but we would never know until we have the technology to travel that far. in billions of years we might not even be able to leave our own galaxy. but who says there is only 1 universe, there is another theory that every time someone is given a choice new reality's open up to all of the choices that person could of made. if you think of the people just on earth not even any other planets in the universe there are 6 billion people on the earth and 1 person is given billions of choices throughout there lives so that equals to trillions and of trillions of parralell universes just on earth.
Well there are many theories on space and it's neverending. But i believe with millions of others that it is in a doughnut shape. just imagine it. it can never end, you can go all the way around and always end where you started. but like i said there are many other theroies. Hope This Helped
