"Finally someone real.," one follower simply commented.
"Thank you for being so real in a world of fake," another added.
"I CANNOT WAIT for you to be a mother and teach another human being that ALL bodies are beautiful. You're going to be such an amazing mother," a third said.
"You continue to set the bar for real beauty inside and out. Thank you for your transparency."
It also prompted a man to share his view and experience.
"I love seeing this. My Mom she had 10 of us. I remembered as a child seeing her tummy," he said, explaining when she had told him how the stretchmarks were caused it made him feel "sad" for her. "My wife now is on her third trimester. I can see how my unborn son is changing her physical look. Love to all women out there and what you're going through for us men. Any man can drive a straight line, takes an expert to master the curves!"
Graham's post — in which she holds her right breast to show all her stretchmarks — has been liked more than one million times.
The photo has also been met with support from fellow model Lily Aldridge and actress Niecy Nash, who both left a series of red heart emojis.
Hillary Scott, of music band Lady Antebellum, meanwhile, commented, "My Lord, THANK YOU for this."
Others named her a role model for young girls, with one fan writing, "This is what girls need to see. We need this as a reference for real and relatable. Women young and old. Thank you!"
Graham, who is also known as a body positive icon, married her filmmaker beau Justin back in 2010 and on Wednesday announced they were expecting their first child at the end of the year.
"Nine years ago today, I married the love of my life. It has been the best journey with my favourite 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," the Swimsuits For All collaborator wrote on her social media.
"Can't wait to meet you," she said in a separate post flaunting her baby bump.
The post came days after Kourtney Kardashian shared a similar Instagram post — an unedited photo of herself in a bikini.
Kourtney, 40, posted a photo of herself wearing a strappy black swimsuit aboard a luxury yacht to her lifestyle blog account POOSH.
Fans of the mum-of-three were quick to spot Kourtney's "stripes" on her upper left thigh, praising the Keeping Up With The Kardashians star for not airbrushing them out and keeping it "real".
