YA Werewolf Book from the 90's

Hi!

Trying to find a book I read as a young teen/pre-teen!

What I remember is that the main character, a girl in Jr. High or High School, goes on a camping trip with her class. At night, when they're telling scary stories, one of her classmates tells them that he's a werewolf, and he's going to kill them all. He transforms and attacks everyone, but is fought off after biting the main character.

The rest of the story is her learning her new powers and dealing with the classmate who's come back to school and is promising to get her when the next full moon comes.

Some of these details could be wrong? It probably came out around 1993-1997. Any help would be appreciated.