As she makes her highly anticipated return to the music scene, Jessica Simpson is sharing anecdotes about some of the major changes in her private life that took place during her hiatus.

In a Wednesday appearance on NBC’s “Today,” the singer and television personality told co-hosts Jenna Bush Hager and Willie Geist she hadn’t expected to get pregnant with son Ace, now 11, just four months after she and ex-husband Eric Johnson welcomed their first child, daughter Maxwell, now 13.

“My firstborn is now 13 years old,” Simpson explained. “But when I had her, I was like, ’You know what, I’m gonna focus on the Jessica Simpson Collection and I’m just gonna mom it.”

She went on to note: “I got pregnant four months later, not thinking you could get pregnant while breastfeeding… It’s like, wait, what? I’m the 1%? Of course, I’m the 1%.”

Studies have shown breastfeeding can be used as a temporary form of birth control, known as the lactational amenorrhea method (LAM), since women’s bodies naturally stop ovulating when they exclusively breastfeed their child.

As Planned Parenthood points out, however, there are caveats. The use of a breast pump, or having your child alternate between breast milk and formula, can reduce its effectiveness. About two out of 100 people who use the LAM method perfectly, meaning they exclusively breastfeed their child, will become pregnant in the first 6 months after their baby is born.

Watch Jessica Simpson’s “Today” appearance below.

In addition to Maxwell and Ace, Simpson and Johnson share a 6-year-old daughter, Birdie. The couple confirmed their separation in January after 10 years of marriage.

Simpson’s “Today” appearance included a live performance of songs from “Nashville Canyon, Part 1,” her first collection of all-original music in 17 years, which dropped in March. A followup EP, “Nashville Canyon, Part 2,” is due in September.

As their titles suggest, the two EPs reflect Simpson’s love of country and Americana music while shifting away from the radio-friendly pop that put her on the map in the late 1990s and early 2000s.

In her chat with Hager and Geist, she said the new songs represent “the type of music that I would’ve always been doing, but when you have a record label, you do what they say.”

“I’m a preacher’s daughter,” she quipped. “I’m very obedient, and I just did my job.”