In the second excerpt, Obama reads about the period of time when her husband, former president Barack Obama, was an IL senator - and they were trying to start a family. "And, so I knew that was gonna be a challenge, that I'd have to earn my grace - and I experienced that on the campaign trail", she said. "We are in our pain and somehow think that we are broken", she described her then-feelings and those of many other women.
That fertility treatment helped the couple conceive daughters Malia, 20, and Sasha, 17.
Since 1996, more than a million babies in the U.S. have been born using IVF.
And the campaigner also shared how she and her husband had undergone marriage counseling after their relationship hit a rocky patch.
She also talked about opening up on being physically attracted to her husband in her book. She said the night she learned he won the presidency, she tried to "block it all out". "But it was also risky, deliberately meant to stir up the wingnuts and kooks". "...[I] t's there. I don't know what to tell you", she told Robin.
"For this", she writes, "I'd never forgive him". "What if that person went looking for our girls?" she writes in the memoir. "I'll never forgive him (Barack Obama) for what he did to our United States military by not funding it properly", he added.
Becoming also tells of the hurt Mrs Obama felt at being portrayed as an "angry black woman" by critics after her husband chose to run for president. Donald Trump, with his loud and reckless innuendos, was putting my family's safety at risk. She remembers how her body "buzzed with fury" after seeing the infamous "Access Hollywood" tape, in which Trump brags about sexually assaulting women. "I was, like, 'Dude, you're cute.' But in my mind, I was, like - Off limits".
At times, she feared she was damaging her husband's 2008 presidential campaign, especially after conservatives seized on a line from one of her speeches - taken out of context - that for the first time as an adult she was "really proud" of her country.
Michelle Obama's full interview will air on ABC at 9PM EST Sunday.