Jill Dillard (formerly Jill Duggar) and her husband Derick Dillard of 19 Kids and Counting fame have learned the gender of their unborn baby. They’re having a boy.

E! News reports that three of Jill’s siblings were there with her and Derick when they learned whether their baby was a boy or a girl. Joy Duggar, who is 16, James Duggar, who is 13, and Jenny Duggar, who is just seven, accompanied Jill and Derick into the ultrasound room.

“Oh yes, there was some screaming in the room,” Jill Duggar said. She also shared that she is 18 weeks along in her pregnancy.

“I thought all along we were having a girl. Everyone made their guesses,” she added.

WATCH: Jill and Derick Duggar Dillard are LIVE at 8:30am ET talking big baby news! #PEOPLENow http://t.co/6reEOmTedw pic.twitter.com/6gVYg0BTDj

— People magazine (@peoplemag) October 23, 2014

Derick Dillard had just one wish.

“I was praying for a big, healthy baby,” he said the night before their ultrasound appointment. “And Jill added, ‘Just healthy, healthy.'”

“We could have a giant,” Jill said of of their baby. “I called Derick’s mom and she was telling me that when Derick was born, he didn’t fit into the newborn clothes and his shoes were a size two.”

“He stretched out his legs full length,” she said of the baby during the ultrasound. “He was trying to be like Dad.”

Jill Dillard recently hinted that she is willing to go the way her parents, Jim Bob and Michelle Duggar, went with regard to the size of their family.

“We are open to as many children as God will give us,” she said in a recent interview.

That certainly makes it sound like Baby Dilly–as the couple has affectionately called their unborn baby since they learned of his existence–likely won’t be an only child.

Derick and Jill Dillard have created a baby registry at Walmart, and have registered for some rather unusual–however frugal–items.

Jill Duggar and Derick Dillard's Walmart baby registry includes requests for orange Gatorade, a fitness ball, & more: http://t.co/9petRWLEwY

— Us Weekly (@usweekly) October 22, 2014

It must have been incredibly exciting for Jill Dillard, her husband, and her accompanying family members to learn the gender of their unborn baby. Jill Duggar is certainly all grown up–isn’t she? And sister Jessa Duggar will tie the knot within a couple of weeks. How long do you suppose it might be before she and Ben Seewald announce that they are expecting, too?