Christina Anstead's Unborn Baby 'Moving Like Crazy' at 21 Weeks

Christina Anstead is already struggling to keep up with her upcoming baby's energy.

The Flip or Flop star took to Instagram Thursday to share a pregnancy update, sharing that her unborn child is already moving "like crazy!"

"#21 weeks ... had our big 20 week ultrasound yesterday - baby is healthy and moving around like crazy!" Anstead wrote on the caption of a new mirror selfie, showing off her adorable baby bump.

"Fun fact according to baby center app- baby is the size of a [carrot emoji] ([Ant Anstead] loves these food comparisons [winky face])," she added.

Fans of the Christina on the Coast personality took to the comments section to compliment the mother-to-be on her glowing look.

"You look amazing!!" one fan commented.

"Oh my goodness! Look at how cute your bump is!!!" another fan wrote.

"Your so tiny [heart eyes emoji] I was a huge whale at 21 weeks [laughing out loud]," a third fan wrote, relating her own pregnancy experience.

Anstead and husband Ant broke the news they were expecting their first child together back in March. The couple tied the knot in December and reveled the baby is due in September.

"[Ant Anstead] and I are so excited to announce [Baby Anstead] coming this September," Christina wrote on Instagram at the time. "The kids are all so excited to meet their new sibling [number five]."

"And then…… there were FIVE!!!" Ant wrote on his own page. "(Well …. four and a half! Will be Five in September)!!"

Anstead also shares two children with ex-husband Tarek El Moussa, son Brayden James, 3, and daughter, Taylor Reese, 8, and Ant is already dad to son Archie, 12, and daughter Amelie, 15, from a previous marriage.

Back in March, El Moussa mistakenly leaked the gender of his ex-wife's baby in an interview.

"She's remarried, she's actually pregnant — everybody knows that," he told the outlet. "She's having a son."

"My kids are super excited. I'm excited for her new chapter in life. And they're a great couple and I really do hope the best for them," he added at the time.

Anstead has kept fans up to date on her latest pregnancy on social media ever since, including weekly photos of her growing bump. She also recently opened up about her difficult first trimester.

"Nausea, exhaustion, too many food aversions, too many carbs.... anyways I'm officially back to feeling somewhat normal. Going to try and enjoy the second trimester while it's here. Thank you to my amazing husband for being so supportive while his new bride was complaining and a little more cray than usual," she wrote in March.