We don't know it for real and the concept "shape" may only focus on a small part of our perception which is partial as well.
If only we could see the whole it would surprise us that it can be ball-shaped, flat, hollow, convex and toroidal at the same time. What part of the truth are we looking for?
The fact is that we're (trapped) here and nobody has the means to get far enough away to show us without filters. Do you?