Ben and Jessa Seewald (left) and Jill and Derick Dillard (pictured with son Israel) discussed their desire to adopt during "Counting On" episode 3. TLC

The Duggars had babies on the brain during the final installment of TLC’s “Jill & Jessa: Counting On” Sunday night. Before Jessa Seewald introduced her first child, son Spurgeon Elliot, to viewers, Jill Dillard opened up about her desire to adopt and spoke out about ongoing pregnancy rumors.

During the special, Jill and her husband, Derick Dillard, who welcomed son Israel in April, continued their mission trip in Central America. After volunteering at a children’s home, Derick, 26, revealed that he and his wife are considering adoption. “I’m excited to see where the journey takes us and what the future looks like,” he said. “As a family, I think this is really a place we could grow.”

Jill, 24, added that they could potentially add one or two new family members while on their extended mission trip. “Who knows? We came down to Central America as a family of three. We could go home as a family of four, or more!”

Before fueling new pregnancy rumors, Jill made it clear to viewers she is not expecting another child. “I’m not pregnant,” she clarified. “Everybody always asks.”

Jill was last rumored to be expecting a second child in August after posting an Instagram video of herself playing with Israel. Fans commented that Jill, who could be seen pushing her then 4-month-old son on a playground toy in the footage, appeared to be sporting a baby bump underneath a loose-fitting shirt.

While fans wait to hear about a possible new arrival for Jill and Derick, Jessa and husband Ben have made it clear they’re planning to adopt, and soon. The couple revealed during Sunday's “Counting On” episode that they plan to continue researching adoption in the coming year. Jessa, 23, said she would “love to” have 19 sons, which is a lifelong dream of Ben’s. Jessa and Ben welcomed Spurgeon Nov. 5.