In the black-and-white pic, the 31-year-old artist tosses back her long locks and clutches a bouquet of flowers in a cute dance pose.
Costabile, an entertainment reporter and TV personality, lookes ecstatic as he admires his now wife while cradling her baby bump.
“On this day four years ago, we met. today, WE GOT MARRIED!!! ??????,” Perri joyously captioned the post.
The couple got engaged in June, with Costabile sharing how it was love at first sight when Perri came in for an interview.
"I knew I wanted to ask this girl to marry me the day she walked into the green screen for an interview almost 4 years ago," he wrote on Instagram. "I finally asked her right here tonight and she said yes!”