I took a self portrait with my fuji instax mini 7s but when the film came out, it was just white. I waited a few more minutes but it still didn't have the picture i took. What's wrong?

White film mean the film is expose to light. and didn't developed properly.
Take a few more shot and try if next few films are the same.
If not, try a new pack of film and test it.

If still the same, mean the lens is spoil. send it to passiongadgets.com at Singapore to repair it.

It comes out white cause you just took the picture. It takes a few moments to "develop" the picture that will be on the card. If you don't see nothing maybe the lens was covered...but it most likely be black as in something was on the card and developed.
how to load film here:
http://www.youtube.com/watch?v=Vq8JguPxq3w


see more here:
http://www.youtube.com/watch?annotation_id=annotation_90634&feature=iv&src_vid=Vq8JguPxq3w&v=-00VbGm3uzs