Before I Fall by Lauren Oliver

What if you had only one day to live? What would you do? Who would you kiss? And how far would you go to save your own life?
Samantha Kingston has it all: the world’s most crush-worthy boyfriend, three amazing best friends, and first pick of everything at Thomas Jefferson High—from the best table in the cafeteria to the choicest parking spot. Friday, February 12, should be just another day in her charmed life.
Instead, it turns out to be her last.
Then she gets a second chance. Seven chances, in fact. Reliving her last day during one miraculous week, she will untangle the mystery surrounding her death—and discover the true value of everything she is in danger of losing.