LITTLE ROCK, Ark. (AP) – No. 19 caught Michelle Duggar by surprise.

The 42-year-old mom of 18 noticed that she wasn’t losing weight – even though she and husband Jim Bob were on Weight Watchers – and her youngest child, 8-month-old Jordyn-Grace, was fussing while nursing. In the past, she found a fussy infant meant a change in breast milk that came with pregnancy.

So she took a pregnancy test. “And lo and behold, I was just pleasantly surprised that this was positive,” Duggar said Tuesday. “I was just jumping up and down going, ‘Thank you, Lord. Here am I – 42, thinking my baby days are over – and you’ve blessed us with another one.'”

Michelle and Jim Bob Duggar live in Tontitown, Ark., and are featured with their family on TLC’s “18 Kids and Counting.”

The announcement of the Duggars’ 19th child comes as their oldest, 21-year-old Josh, is about to become a father himself. Married last year, Josh and Anna Duggar are expecting their first child, a girl, on Oct. 18.

The grandchild – whom Josh and Anna plan to name Mackynzie – will be about five months older than her future aunt or uncle, due March 18.

Michelle Duggar said her health is fine and the pregnancy is going along just like the others – with a decent bout of morning sickness.

“I am just so grateful that I have good health thus far and I’m just enjoying playing with my kids every day,” she said. “I don’t take that for granted one bit. I still have a lot of energy left.”

They’re soliciting name suggestions for the new baby, who will join their family of 10 boys and eight girls. The Duggars’ 18 children all have names starting with the letter J and include two sets of twins. Along with Josh and Jordyn-Grace, the family includes: Jana and John-David, 19; Jill, 18; Jessa, 16; Jinger, 15; Joseph, 14; Josiah, 13; Joy-Anna, 11; Jeremiah and Jedidiah, 10; Jason, 9; James, 8; Justin, 6; Jackson, 5; Johannah, 3; and Jennifer, 2.

The Duggars live in a 7,000-square-foot house in northwest Arkansas, where they manage commercial real estate property. They say they’ll keep welcoming more children as long as Michelle is able to have them.

Michelle Duggar says they’re recognized regularly thanks to the TLC show.

“We feel like it’s just an opportunity to encourage families to enjoy their children, enjoy children while they have them and realize that they are a gift from God,” she said. “That’s our prayer. This is an opportunity to just encourage others to value family and just enjoy the time you have with them.”