The mother of three sat down with Meyers on Thursday's Late Night to promote her new film, Miracles From Heaven, and the expectant father hit her up for some guidance.
Her advice? Don't listen to anyone's advice, including the kind found in books about raising babies.
"It's not up to you dude," Garner said. "It doesn't matter, let it go, don't worry about it. You're going to struggle, it's going to suck, just like for everyone else."
While most would agree her words of wisdom were accurate, they didn't seem to ease Meyers' mind about the upcoming addition to his family. But he did seem excited to tell his wife they could throw away all the baby books they bought.
"You don't say that to her!" Garner scolded Meyers. "Do not say that to her!"
"I've pretty much stopped saying anything to her," Meyers quipped.
Finally, Garner spelled out what the experience of having your first child is really like in even simpler terms: "Just know in your head, 'This is all going to go to hell in a hand basket.'"
Garner welcomed her first child, daughter Violet, in December 2005 with her then-husband, Ben Affleck. The couple, who announced they were splitting last June, also share 7-year-old daughter Seraphina and 4-year-old son Samuel.
Garner's faith-based drama, Miracles from Heaven, which opened on Wednesday, was the first film she worked on after news broke of her divorce. In the film, she plays the mother of young girl who is suffering from a terrible disease. After her daughter suffers a near-death experience, she is miraculously cured of her terminal illness.