Bristol Palin calls her ex 'a gnat' in new book

By FRAZIER MOORE | June 17, 2011 | 8:43 PM EDT

FILE - In this Nov. 24, 2010 file photo, former "Dancing with the Stars" contestant Bristol Palin arrives for an appearance on ABC's "Good Morning America" in New York. The daughter of former Alaska governor Sarah Palin has a memoir published by William Morrow called "Not Afraid of Life," expected this summer. (AP Photo/Charles Sykes, File)

NEW YORK (AP) — Bristol Palin writes of losing her virginity to boyfriend Levi (LEE'-vy) Johnston on a camping trip after getting drunk for the first time.

Later, she got pregnant while on birth control pills she took to control cramping.

Palin is the daughter of former Alaska Republican Gov. Sarah Palin and is a 20-year-old single mother. She tells a story of "deception and disappointment" in her new book, "Not Afraid of Life: My Journey So Far."

Her book is scheduled for publication next week. It covers growing up with her family and the excitement of her mother's political life.

But the main theme is her now-estranged relationship with Johnston, the father of her son. She calls him "a gnat."

Johnston has promised to set the record straight in his own book, "Deer in the Headlights: My Life in Sarah Palin's Crosshairs."