Jill Duggar of 19 Kids and Counting is still carrying Baby Dilly around after they missed his first due date on March 24, and her husband Derick Dillard is wondering when their new baby will decide to arrive.

On his Instagram account (@derickdillard), he posted a photo of Jill with her biggest baby bump yet. She was sporting glasses and a simple grey t-shirt and carried the signboard saying "40 Weeks 2 Days."

He captioned it, "I wonder if #babydilly will decide to come on the one year anniversary of my engagement to@jillmdillard this weekend."

Derick proposed to Jill on March 29, 2014 and they were wed in June that same year.

Derick is beyond excited for Baby Dilly's arrival and his engagement anniversary with Jill. He earlier posted a photo collage of himself wearing a "#newdad" t-shirt, a "Dad-to-Be" mug, and Jill carrying a signboard saying "39 Weeks 4 Days."

"A LOT has happened since June 21! I am blessed beyond measure and every day is even better with you baby! You're my best friend, and I love you with all my heart!" he wrote alongside the photo.

The expectant dad shared a conversation he had with his mother Cathy Byrum. "My mom has said that once #babydilly is born, she will be an 'insta-gram," he laughingly shared.

Jill's next due date has been set on April 5, according to PEOPLE, and she said during the interview that she isn't worried a single bit because they were "planning on the baby coming late."

It's "no big deal – if you have it in your head that way, you won't get discouraged," she said.

In fact, it's her father Jim Bob who is more worried about his daughter and new grandson. Jill has been suffering from Braxton Hicks contractions and it's making the Duggar patriarch very anxious.

"He's checking in, asking how regular they are," Jill says with a laugh. "I feel great, the baby is moving around a lot."