Lauren, 30, posted footage from an ultrasound appointment on Instagram and wrote, "A dream, except I'm not dreaming."
"I'm wide awake," she continued. "Holding your dad's hand, watching you dance around in my belly. Listening to your little heart beat. My new favorite sound. A miracle. New life. Our sweet baby. Thank you Jesus! All the glory belongs to You."
Ben, 31, commented on Lauren's social-media post, "Congrats! What a thing to celebrate!"
FOLLOW REALITY TV WORLD ON THE ALL-NEW GOOGLE NEWS!
Reality TV World is now available on the all-new Google News app and website. Click here to visit our Google News page, and then click FOLLOW to add us as a news source!
Lauren told the magazine earlier this year her "No. 1 goal" was to start a family with Chris soon.
"Career stuff is amazing and I feel very blessed, but I've always wanted to be a mom. I'm excited, that's my number one most exciting next chapter," Lauren said at the time.
This past summer, Lauren shared a touching post about how she and Chris were hoping to get pregnant as soon as possible.
"We got engaged about a year ago and y'all, I don't know what I did to deserve this man. About to get personal but I am very excited to start a family and get asked when we are having kids ALL the time but it just hasn't happened yet," Lauren wrote in June.
Lauren recalled how Chris asked Lauren to pray about it and the baby would come at the right time.
"I am so lucky I get to wake up next to you every morning, lucky I get to pray next to you and am continually humbled by your heart of gold," Lauren concluded.
Lauren also previously told Us Weekly that she "wants a lot" of children since she grew up with three siblings.
On The Bachelor's 20th season, Lauren and Ben got engaged during the finale that aired in March 2016, and it was widely believed Ben had nothing but the best of intentions and the couple was truly in love. Lauren even moved from the home she loved in California to be with Ben in Denver, CO.
Shortly after going public with their breakup, Ben said on his The Ben and Ashley I: Almost Famous Podcast, "I think mutually Lauren and I saw that life was getting more difficult."
"I would say the joy that we felt toward our relationship at the beginning was -- for some reason -- slipping away," Ben added.
"And we were both working very hard to bring that joy back. And it just never seemed to get there. So it was a long time coming but it wasn't necessarily like we dragged it out."
In June 2018, Lauren explained on Reality Steve spoiler blogger Steve Carbone's podcast there was not "one main reason" why her relationship with Ben failed.
"It wasn't this bad blood situation or blow-up fight -- it's nothing I can really pinpoint. It just came down to compatibility... I don't necessarily think at the end of the day we were the most compatible," Lauren said at the time.
"Coming out of a show like The Bachelor is very stressful," admitted Lauren, who said she craved normalcy after getting engaged to Ben.
While Lauren was dealing with negative press -- including gossip about Ben's love for JoJo Fletcher on his season -- and trying to adjust to her new life with Ben in Denver, the pair starred in a Freeform spinoff titled Ben & Lauren: Happily Ever After?, which featured a lot of ups and downs in their relationship.
Ben proposed marriage to Jessica back in March in her hometown of Franklin, TN.
As for Lauren's love story, she met Chris in 2015 at a radio event in Austin, TX, but they started out as friends.
Chris "randomly asked" Lauren in August 2018 to join a group of his friends for a Bahamas vacation and that's when their mutual attraction became known. However, neither person acted on his or her feelings because they both said they had walls up at the time, according to People.
Once Lauren returned to Los Angeles, CA, and Chris returned home to Nashville, TN, he said he couldn't get the blonde beauty off his mind.
Daily calls therefore led to more hangout sessions, and then the couple went public with their romance in November 2018 when they walked the red carpet together at the CMA Awards.