From Jukes (I'll See You in My Dreams, 1993, etc.), sixth-grade comedy v‚rit‚: Sexeducated to the max, River is awaiting her first period (which she doesn't get). She is certain that her older sister, Megan (""The Royal Queen of PMS"" and ""Her Premenstrual Majesty"") is pregnant (she's not) and doesn't notice that her mother's new baggy look conceals an unplanned middle-age pregnancy--the ""unexpected"" of the title. Adding to the hormonal overload, River's cat is pregnant (Mom didn't get around to having her neutered). River admires classmate DB who looks ""great in his Nike T-shirt"" and who takes ""the rap for the girls"" in the class campaign to haze their decent, nice-guy teacher. It's all skin deep, but the book is occasionally hilarious, thick with teenspeak and oneliners about everything from PMS to ""Wedgie Hell.