You said no when it asked you whether to save it or not ?
Good luck explaining that to your teacher.
( Been there done that. The most effective solutions are
1) Make notice to your teacher asap, ask him/her for a few days of extension.
2) Play silent, toil day and night redoing the work. Trust me it pays back later if you do it right. I spent 2 nights not sleeping after a power failure telefragged my work. I got 95% mark on that piece.
Again, good luck !
)