Make way for more Duggars!

Jim Bob and Michelle Duggar of Tonitown, Ark., who have 18 children and one grandchild on the way, are expecting a new addition to their household – baby No. 19 will arrive in the spring.

“We are so thrilled,” says Michelle, 42. “We just couldn’t believe it is happening.” Jim Bob, 44, agrees: “This never gets old. We are so grateful for each child. We are looking forward to our first grand baby and our 19th child.”

Oldest son Joshua, 21 and his wife Anna, 21, are expecting daughter Mackynzie Renée next month, so she will be older than her new aunt or uncle.

“I think it is going to be awesome, it is going to be great,” says Josh about the news that his parents are expecting. “We have been looking forward to the arrival of my little girl and to now get to celebrate for my parents, it’s a wonderful thing.”

Another Fun Pregnancy
The families often get to see one another and are looking forward to the babies’ births.

“I love all of this, it is so fun,” says Michelle. “Anna and I will have babies five months apart. My mother and my sister were pregnant at the same time and it was really wonderful. The kids were really close and still are. I have a nephew who grew up with me, we’re just three months apart.”

The Duggars live debt-free in a house they built themselves with their kids, whose names all begin with J: after Josh there are twins Jana and John-David, 19; Jill, 18; Jessa, 16; Jinger, 15; Joseph, 14; Josiah, 13; Joy-Anna, 11; twins Jedidiah and Jeremiah, 10; Jason, 9; James, 8; Justin, 6; Jackson, 5; Johanna, 3; Jennifer, 2, and Jordyn-Grace, 8 months. Their lives are featured on TLC’s 18 Kids and Counting, airing Tuesday nights.

Surprised This Time
Despite being pregnant 18 times before, Michelle says this pregnancy came as a shock, although her daughters wondered why she was eating more pickles than usual.

“I was wanting pickles and the older girls were saying, ‘Mom, you only crave these at the very beginning of being pregnant, You kept it from us before, now tell us. Are you?'” Michelle says. “And I kept telling them I wasn’t. I just wanted some pickles.”

But when she couldn’t lose weight on her diet, she became suspicious.

“I was in Weight Watchers with Jim Bob and I wasn’t losing any weight,” she says. “I couldn’t figure it out. I was doing what I should. And the baby, who was nursing, was fussy. I kept thinking, ‘This isn’t right. She isn’t teething, she doesn’t have an ear infection. I’m not cheating on my diet, I should be losing weight.’ Then, I put two and two together and wondered if I could possibly be pregnant.”

She took out one of two tests she had in the house and it was immediately positive.

Renewed Marriage Vows
“I told Jim Bob and he couldn’t keep it in, he was so excited,” she says. “The kids were outside playing on a water slide and he gathered them together and had to share the news. There was all this screaming and yelling.”

The Duggars recently renewed their wedding vows – they’ve been married 25 years and one month – and say that the ceremony was a wonderful way for their own children to understand the commitment of marriage.

“We got married when Michelle was 17 and I was 19,” Jim Bob says. “We were married in the hallway of a church because at the time they had no sanctuary. There were plastic chairs and crepe paper. So, when we renewed our vows, we did it in that same hallway and we splurged to make bows out of a plastic white table cloth this time, but we still had plastic chairs. I think it is important to have the kids see that commitment themselves.”

No Health Concerns
Michelle says that since she was 36 years old, her doctor has given her and Jim Bob pamphlets about prenatal testing since there is an increase of risk of health problems in babies with older mothers. But, she says they don’t worry about those risks and don’t take the tests.

“We know what could happen,” she says. “We read through the information. If the Lord chooses to give us challenges along the way, we know His grace will be there, so we don’t opt to do the testing.”

As far as her own health, her doctor told PEOPLE when her last child was born that Michelle’s health was excellent: “Some women are made to have babies, and Michelle is to the nth degree,” ob-gyn Amy Sarver told PEOPLE in December. “She is in terrific health without any strain on her uterus.”

Michelle says she’s just glad for every day that she gets to enjoy being with her kids, even as she endures a 19th round of morning sickness.

“I’m feeling nauseous right now,” she says. “And, I’m tired. I am happy for the feelings of morning sickness and I’m happy for every day I get to play with my kids. We don’t know what tomorrow holds and so I try to enjoy every moment.”

Another J-Name
Already, names are being discussed in the Duggar household: Jessa, 16, has printed up a list of J-names for boys and girls that have yet to be used by a Duggar, Michelle says.

“We’ll hopefully find out whether it’s a girl or a boy at 20 weeks,” says Jim Bob. (Michelle is almost at the 12-week mark now.) “That will narrow the list down some.”

And Jim Bob says he’d welcome a little assistance: “We’d love to hear from the readers at to come up with a special name for this child.”