Josh and Anna Duggar Are Expecting Baby Number 4

— -- Jill Dillard isn't the only pregnant person in her family!

Anna Duggar, who's been married to Josh Duggar since 2008, is pregnant with the couple's fourth child, she announced on Twitter.

"We are so excited to announce...we're pregnant!" she wrote. "#4andCounting #BlessingfromTheLord @joshduggar #19Kids"

The "19 Kids & Counting" stars, both 26, are already parents to three children: Mackynzie, 5, Michael, 3, and Marcus, 18 months.

It's been an exciting year for the family: Jill and Derick Dillard are expecting their first child, a boy, next year, and Jessa Duggar wed her husband, Ben Seewald, last month.