Michelle Obama says she felt alone after a miscarriage 20 years ago and she and Barack Obama underwent fertility treatments to conceive their two daughters, according to her upcoming memoir, "Becoming." The memoir is one of the most anticipated political books in memory, ranking at the top of Amazon's best-sellers on Friday, and Obama will launch her promotional tour Tuesday at Chicago's United Center, where tens of thousands of people have purchased tickets — from just under $30 to thousands of dollars — to attend the event moderated by Oprah Winfrey.