Happy Birthday to Kristin Cavallari and Jay Cutler's little boy, Camden!

Kristin Cavallari Gives 'Intimate' Look Into Her Life As A Wife & Mother

On Saturday, the oldest child of the reality star and her husband turned three-years-old. Cavallari took to Instagram to post an adorable black and white snapshot of her child when he was a baby, writing a thoughtful message in the caption. She referred to her son as her "whole world."

See the picture below.

Kristin Cavallari Bares Her Healthy Figure On Social Media

Later that day, Cavallari posted a photo of her son with his daddy as they were walking into a sports field. Camden held his father's hand as the two walked off in the distance in what appeared to be a wonderful day.

A photo posted by Kristin Cavallari (@kristincavallari) on Aug 8, 2015 at 11:57am PDT

Cavallari and Cutler are also parents to their one-year-old son, Jaxon. The former Hills star is also pregnant with the couple's third child who is expected to be a girl. She will likely be brought into the world sometime this fall.

In a previous Instagram image, Cavallari showed off her pregnancy body where she looks healthy and glowing. As she dons a black dress with brown boots and a jean jacket, the 28-year-old holds her pregnant belly as she explores life in the city.

 City life today

A photo posted by Kristin Cavallari (@kristincavallari) on Aug 4, 2015 at 2:55pm PDT

Cavallari and Cutler have been married for two years now.