Joy-Anna Duggar welcomed a new baby to the family only four months after marrying husband Austin Forsyth – but he isn't theirs! The Counting On star introduced her new nephew to social media.

"Welcome to this large and one of a kind family Mason Garrett Duggar," Joy-Anna tweeted of her brother Josh and sister-in-law Anna's fifth child.

The next baby to join the Duggar family will be Joy-Anna and Austin's. The couple announced their pregnancy earlier this month, only three months after their wedding.

The shotgun wedding rumors began when they moved the wedding up from October 28 to May 26, 2017.

When she showed off her bump, fans didn't believe she was only three months pregnant.

Dr. Stuart Fischer, who has not treated Joy-Anna, told Breaking Celebrity News that the mom-to-be looks "four to five months pregnant" based on the bump photos.

The couple even admitted to breaking courtship rules in the past.

Austin touched his then-girlfriend's hand while renovating a home even though couples are not allowed to hold hands until they are engaged.

When she accepted his marriage proposal, she gave him a full hug instead of a side hug.

"We're humans and sometimes we don't always abide perfectly by our rules," he said during a Counting On reunion special. "We try. That was a real hard try."