Transcript for Michelle Obama on her marriage, husband's grueling campaign
There are many things in reading your book that I don't think I would ever imagine hearing from a first lady. Lust. You talked about lust for your man. Uh-huh. It was there. It still is. I love my husband. A lot. Her new book, becoming, is a personal look at her life. Inside and out of the white house. By age 25 Michelle executed a meticulous game plan for achievement and success. Got into princeton. Why don't I go to law school. I got into Harvard. Got the big firm position. Check. Still a law student at Harvard. First year. You are going to be his mentor. Late for the first meeting. Late. Is he trying? You were not overly impressed in the beginning. I wasn't. I had suspicions when a bunch of white folks faun over a black man. They think he is wonderful. In walks Barack Obama. Barack Obama has always walked like Barack Obama. He's got all the time in the world. Dude, you're cute, but in my mind, I was like -- Not interested? Off limits. Not even not interested. I'm not going toidate one of the few black soeshts. How tacky. By July her resolve to begin romance began to falter. He was like you're crazy. I like you and you like me. We should date. He was not playing games. When we stopped for ice cream, he played it real smooth. He just leaned in for a kiss. That really was it. From that kiss on, we were -- it was love. He was my man. Now for the first time, Michelle is open up about parts of their marriage she held deeply private for years. First, infertility. It turns out that two committed go getters with a deep love and robust work ethic can't will themselves into being pregnant. She did get pregnant, but weeks later, she miscarried. I feel like I failed because I didn't know how common miscarriages were because we don't talk about it. It was with the help of infertiity treatments that Malia and then Sasha were conceived. It's the worst thing we do as women is not share the truth about our bodies and how they work and don't work. For the first time she shares details about how the stress of their hectic scheduleless infiltrated their marriage. Marriage counseling was a way where he learned how to talk out differences. What I learned about myself is my happiness was up to me. I know too many young couples who struggle and think that somehow there is something wrong with them. I want them to know that Michelle and Barack Obama who have a phenomenal marriage and love each other, we work on our marriage and get help when we need it. The campaign trail would test her resilience. They called me Barack's baby's mama. Accused me of not loving my country. Said I was angry. You admitted, this stuff hurt. Yeah. The hurt would continue into the white house. With calls for president Obama's birth certificate, questioning his legitimacy. She writes -- It is underlying bigotry and xenophobia hardly concealed, but it was also dangerous, deliberately meant to stir up the wing nuts and the cooks. Why doesn't he show his birth certificate. Donald Trump was putting my family's safety at risk. For this I would never forgive him. Mrs. Obama's influence continues to touch younger generation. Nowhere is she a bigger role model than at Whitney young high school on Chicago's west side. We brought Mrs. Obama back to drop in on a dance class. You see her right now and you would not know she walked these halls saying am I get enough? Pa. I talked about a counsellor who said I was not princeton material. Can you imagine that? She doesn't work here anymore. I get a lot of opposition when I ask for opinions from the student body. I want to accommodate to everyone and make the school a better place. First of all, you stop trying to make everybody happy. It's impossible. As first lady, I wanted everybody to be happy and I wanted everybody to like me. No matter what I did, there was always somebody out there that thought what I was saying was stupid or that can't be your goal. I would love to hug each and every one of you. What do you want your legacy to be? Young people are the future. If my story, my journey somehow gives them hope, if I played a role in that for young people coming down the line, I'll feel good about it.
This transcript has been automatically generated and may not be 100% accurate.