Ashley Graham and Husband Justin Ervin Welcome a Son: 'Our Lives Changed for the Better'

Ashley Graham is a mom!

The supermodel, 32, and her husband Justin Ervin welcomed their first child together, a son, on Saturday, Jan. 18, they shared on their Instagram Stories Monday.

While Graham didn’t share any other birth details, including their baby boy’s name, she did tag her husband in the post (which Ervin, 31, re-shared on his own Story) and wrote, “At 6:00pm on Saturday our lives changed for the better,” adding red and blue heart emojis.

“Thank you all for your love and support during this incredible time,” she addressed her followers in addition.

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Graham announced her pregnancy back in August, wishing her husband a happy anniversary with an Instagram video revealing the news.

“Nine years ago today, I married the love of my life,” she began the post. “It has been the best journey with my favorite person in the world! Today, we are feeling so blessed, grateful and excited to celebrate with our GROWING FAMILY! Happy anniversary, @mrjustinervin ❤️ Life is about to get even better. ?”

Three months later, the model and then-mama-to-be revealed during a visit to The Ellen DeGeneres Show that their bundle on the way would be a son.

“I’m having a boy!” Graham screamed, nearly jumping out of her seat. “I’m gonna be a mommy to a boy!”

RELATED VIDEO: “Surprise!” Ashley Graham Is Pregnant, Expecting First Child with Husband Justin Ervin

Graham has been body positive throughout her pregnancy, posting inspiring messages about self-love, revealing the weight she gained (50 lbs. as of mid-December) and posting nude photos showing her stretch marks.

During a November episode of her digital series, Fearless with Ashley Graham, the star shared that she had been struggling with her “new body” at the time she posted her first nude pregnancy photo.

“I had just announced that I was pregnant and I thought then I was going to feel good and I didn’t. I just felt terrible. And that morning, actually … ” she said, stopping as she began to cry. “I was like, ‘Get it together, Ashley, there’s other women out there that are going through the same thing as you — why don’t you have a dialogue?’ ”

Adding that the experience of having a “new body” made her feel “so isolated” and “so alone,” Graham noted that pregnancy has meant having “to come into this new world of body confidence.”

That same month, the couple celebrated their son at a “very nontraditional” baby shower at The Foundry in New York City alongside friends and family.

For partygoers, including Gayle King, there were stations around the venue to get free manicures, tattoos and even piercings, as a rep for Graham told PEOPLE and journalist Derek Blasberg captured on his Instagram Story.

Graham told Jimmy Fallon in December that her pregnancy felt “like a sci-fi film every day.”

“There’s like a little alien taking over my stomach, and I swear he’s on a treadmill. And one day he’s just gonna be running out of me!” she joked. “At least, that’s what I’m hoping for.”