The pro dancer announced she and her husband are expecting their first child together, live on Monday's Dancing with the Stars live show

An exciting announcement was made on Dancing with the Stars Monday night, and it had nothing to do with the competition.

Professional dancer and last year’s runner up Allison Holker shared the news that she and her husband, Stephen “tWitch” Boss, are expecting a baby together.

“This was such an amazing night and I’m so glad the news is finally out there,” she told PEOPLE after the show. “It has been so hard to keep it bottled up inside me — both literally and figuratively!”

She adds, “I’m so excited for everyone to know and be able to celebrate with us because our whole family is just so excited about this. It’s the biggest blessing.”

Holker made the announcement in the green room before she and her partner, Andy Grammer, took the stage.

Allison Holker Stephen Boss expecting baby

David Livingston/Getty Images

Afterwards, the dancer took to Twitter, sharing a photo of herself with her husband and daughter Weslie Renae, 7, surrounded by members of the Dancing with the Stars cast.

“WE ARE HAVING A BABY!!!!!!!!” Holker captioned the photo. The dad-to-be shared the same snapshot with the hashtag #BabyBoss on Instagram.

After dancing, the former So You Think You Can Dance star revealed that she’s four months along. Holker also said she will continue with the competition while pregnant — a first for the show.

“I’ve had a child before and I worked all the way through eight months. I was traveling on tour, so I think I can definitely handle it,” she tells PEOPLE of continuing to dance.

“This is what I do and what I know. If you were athletic before you were pregnant, you should stay athletic. I’m not scared of the challenge and I think it’s a beautiful thing to experience.”

The baby on the way will be the first for Boss, but the Emmy-nominated dancer is already mom to Weslie, her daughter from a previous relationship. And the future big sister couldn’t be more excited about her upcoming role.

“She’s ecstatic and already prepping to be the best older sister she can be to the little girl or boy — we don’t know the sex yet,” says Holker. “She’s always been a very helpful child, but it seems like now if I need a glass of water, she’ll be, like, ‘No, no, no mother. I’ll get it for you.’ She helps out and it has been the best energy in our home.”

The pair met as all-stars on So You Think You Can Dance and married in 2013.

Holker opened up to PEOPLE over the weekend about her daughter and making time for family despite her hectic dancing schedule.

“I’m on Dancing with the Stars now and, as the pros, we compact ourselves with so much work that every once and awhile we have to have a family night and let go of all the work,” she saidat the Los Angeles Haunted Hayride VIP Black Carpet on Sunday night.

In some ways, her demanding schedule works in her favor when it comes to parenting.

“It’s the coolest thing because [Weslie] goes to school and [she] and her girlfriends see me as the cool mom,” Holker joked. “I’m not the cool mom where you can get away with everything, but they tell me about the boys and I feel lucky.”

— Naja Rayne with reporting by Patrick Gomez and Nicole Sands