Yes, we are going to go from THAT TO jenny McCarthy. She's pretty fearless, always funny. And in her new book, "bad habits: Confessions of a recovering catholic." I think stephen is going to join in... See More
Yes, we are going to go from THAT TO jenny McCarthy. She's pretty fearless, always funny. And in her new book, "bad habits: Confessions of a recovering catholic." I think stephen is going to join in on our interview. First, a look at a trip home with juju chang. Reporter: She's a mom, an actress, and host of reality show, "love in the wild." DON'T LET jenny McCarthy's look fool you. She's written six best-sellers. Her latest, a funny look back at the naughty schoolgirl who launched her career at 22. She's just posed again 24 last august. Proving she's still got it. She chronicles her devout upbringing in her back. That's my bedroom window. Reporter: She grew up poor with three sisters in a polish neighborhood on chicago's south side. We return to the shows she grew up in. Her initials still carved in cement in the backyard. I see one right there. There's jenny. Reporter: Like a dig. Walking up to the attic of her old bedroom, she recalls dreams of becoming a nun. I had a jesus poster. The pope was over there. Flaming heart of jesus was over there. And I had some, I love jesus t-shirts and bags hanging up. Reporter: Jesus was your bieber. Jesus was my bieber. Reporter: She had dreams of career for two decades. Only returning recently to raise her son. For "good morning america," juju chang, abc news, chicago. And joining us, now, to talk about her book "bad habits: Confessions of a recovering catholic," is actress and best-selling author, jenny McCARTHY. Jesus was your bieber? Jesus was my bieber. You wrote the first time you made out with a boy in your room, you had to cover up the jesus poster. I was making out with a boy. Oh, my god. Jesus is right behind you. So, I pasted cyndi lauper on top of jesus. And it worked. Thanks. I, too, was raised in a very catholic household. We were not, as you call them in your book, creasters. They go to mass on easter and christmas. Every day during advent and lent. Always in the front row. So many catholic stories growing up that everyone can relate to. My biggest fear throughout the book was that I was going to be possessed by satan at any point. And I think "the exorcist," is a great way the catholic church can scare the heck out of you. Really, it scared us to the bone. Me and my sisters slept every night with rosaries and statues. I would have my cabbage patch dolls. I was so scared every night. You wanted to be a nun when you were a little girl. I did. That is until you told a nun you wanted to be a nun and a mom. It's only logical when you start off with a clean slate, they teach you is to do good things to get to heaven. Naturally, I thought it was brilliant. Why wouldn't I take the occupation of being a nun and get a one-way ticket to heaven. Automatic in. That is until we went to the convent one day. My mom is a hairdresser. I saw what they looked like in common folk clothing. And then, had a conversation with them about what I wanted to be when I grew up, which was a mom and a nun. They told me that wasn't possible. I knew that wasn't my destiny. I had to take off the habit and put on a push-up bra. You also took off the push-up bra. How did you go from being a wannabe nun to "playboy" playmate? It was devastating in my childhood to watch my mom and dad struggle for food. Where dinner was going to come from. And there's a part in the book where we thought we won a McDONALD'S LOTTERY. You know, the monopoly things. We thought we were rich. It was the worst three hours of our life. As time went on, I knew I would bail them out someday. And when I posed for "playboy," I went home and wrote a check out for all of their bills and moved them into the suburbs. You also just posed again for "playboy" at the age of 39. I did. Amen. You look fantastic at 39. Did you have to do anything special to get ready for that? No. I hate you. I had to work out, tan and starve. Just that little thing. Just those three things. Everyone said to me in hollywood, women are done after a certain age. And we're not sexy anymore. And I think the word milf was created for a reason because women are looking great later on. I figured why not show it off one more time, as well. You recently moved from southern california, from hollywood, to your hometown of chicago, one of my favorite cities. I love chicago. It's one of the greatest things I've ever done. Why did you move back? And how did that affect, evan, your son? Growing up in chicago, people are like, a sense of community. And go to hollywood, and they're very fake. And I want evan to have the same childhood I did. Hello. Lovely to meet you. A fellow catholic. Do you still have aspirations to be a none? You've dressed in black and white today. No. I think -- no. I think I can get into heaven some other way. The subtitle, "confessions of a recovering catholic." Do you go to mass? I don't go to mass. But I believe in a lot of the things that catholics do. Such as jesus, mary and god. Those things. Are you still a catholic? No. You know you're going to hell, right? Really? I'm just saying. There's only one true bride of christ. It is the catholic church. I don't mean to bring you down at the end. It was a lovely segment. Why don't we break some commandments together. I can teach you. Sure. Dare I ask? I covet your book sales. That's a lot to covet, stephen. I know. "New york times" best seller. It's motivation when you're a singer mom, your kid is hungry, you're going to come up with ideas to write some books. Best midnight mass story, i set my hair on fire. Yours? I was an alter boy. The priest would make us bury the incense from mass. I stole all of the money baskets. What? Oh, my gosh. jenny McCarthy's books in stores now. Live from wcvb tv channel 5,
This transcript has been automatically generated and may not be 100% accurate.