Jana Duggar's on her way to 19 kids -- if she's following the family pattern -- because she gave birth to her first child just a few weeks ago!

Waiting for your permission to load the Instagram Media.

The reality television star shared the happy news Friday ... posting several pictures alongside her husband, Stephen Wissmann, with their new son between them -- not quite smiling, but certainly unperturbed by the camera.

Duggar wrote in her caption they named their son Archie Gerald Wissmann ... and he was born on December 30 -- but the new parents wanted to take their time in announcing the birth.

She writes, "Our hearts have been completely changed. We’re soaking in these early days, full of love, wonder, and so much gratitude."

Waiting for your permission to load the Instagram Media.

Jana announced she was expecting back in August with a sweet photo shoot ... and, though she originally said the child would be arriving in January, it seems little Archie couldn't wait to get out into the world.

Jana is the eldest daughter of Jim Bob and Michelle Duggar ... and she made frequent appearances on "19 Kids and Counting" and later its spinoff "Counting On."