Why My Kitten Bites My Face?

i have a female kitten who is about four months old. she has bitten me once before, but i didnt think it was that bad since she only bit the tip of my nose haha! this time though, when i tried to pet her she attacked my face really hard and started biting my cheek!!

i dont know what could be wrong with her or why she would attack me like that? please help!!!