Kunis, 30, got engaged to her boyfriend (and former "That '70s Show" costar) Ashton Kutcher last month. It will be the first child for both actors.
Kunis and Kutcher started dating back in 2012, following Kutcher's high-profile split from wife Demi Moore back in 2011. Their divorce was finalized last October.
E! reports that Kunis was recently spotted at a prenatal yoga class. They also say that rumors Kunis is pregnant with twins are false.
Perhaps Kunis's pregnancy explains her reduced role in the "Ted" sequel?
Photo by AP Photo/Danny Moloshok
Gallery | Celebrity Couples Who Met on Set
- Humphrey Bogart & Lauren Bacall
Bogart, 45, was on his third marriage when he met 19-year-old Bacall on the classic “To Have & Have Not” in 1944. They wed the next year; the marriage lasted until his death in 1957. They costarred again in “The Big Sleep,” “Dark Passage” and “Key Largo.”
- Elizabeth Taylor & Richard Burton
One of the biggest Hollywood scandals occurred in 1962, when bombshell Taylor, then married to husband No. 4, Eddie Fisher, and “Cleopatra” love interest Burton were photographed off-set looking very cozy. They both divorced their spouses and married in 1964. They divorced in 1974. They remarried in 1975 but called it quits for good in 1976.
- Ali MacGraw & Steve McQueen
MacGraw was married to her “Love Story” producer, Robert Evans, when she began an affair with McQueen on the set of 1972's “The Getaway.” She and the action star married in 1973 but divorced in 1978. McQueen remarried in 1980, the same year he died of cancer.
- Tom Hanks & Rita Wilson
The pair had previously met on Hanks's TV show “Bosom Buddies,” but struck up a romance as co-stars in 1985's “Volunteers.” Twenty-plus years and two kids later, they're still going strong. (Hanks's kids, Colin & Elizabeth, are from his previous marriage to Samantha Lewes.)
- Susan Sarandon & Tim Robbins
The politically minded couple met during the steamy baseball comedy “Bull Durham” in 1988. Two children, two Oscars (one each) and 21 years later, they unexpectedly split in 2009. She had previously been married to “Fright Night” star Chris Sarandon.
- Julia Roberts & Kiefer Sutherland
This unlikely couple met while making the 1990 thriller “Flatliners.” Their engagement ended when he reportedly stepped out with a stripper: She responded by fleeing with his BF, Jason Patric. After making 1992's “The Player,” she briefly married her co-star, country singer Lyle Lovett. She's now married to Danny Moder, a cinematographer on her 2001 movie “The Mexican.”
- Warren Beatty & Annette Bening
Beatty had been one of Hollywood's most notorious playboys who would seemingly never settle down when he and Bening starred in the 1991 mob saga “Bugsy.” They married in 1992, had four children, and have now been married more than 20 years.
- Reese Witherspoon & Ryan Phillippe
Witherspoon considered Phillippe her “birthday present” when he came to her 21st birthday party. They were already a couple by the time they starred together in “Cruel Intentions.” They married in 1999 and had two children but divorced in 2007. She's now remarried.
- Courtney Cox & David Arquette
Their romance began on the set of the 1996 horror film “Scream.” By the time “Scream 3” came out in 2000, they were married; daughter Coco was born in 2004. They separated in 2010 and divorced in 2012.
- Uma Thurman & Ethan Hawke
Their onscreen romance in the 1997 futuristic thriller “Gattaca” led to marriage in 1998 and two kids. They divorced in 2005. She had previously been married to Gary Oldman, who had a small part in her 1990 film “Henry & June.”
- Meg Ryan & Russell Crowe
Fans of rom-com sweetheart Ryan were shocked when photos surfaced of her kissing her “Proof of Life” costar Crowe in 2000: What they didn't know is that her marriage to Dennis Quaid (whom she'd met while making 1987's “Innerspace”) was essentially over. The relationship was short-lived; Crowe married old Aussie flame Danielle Spencer in 2003 and Ryan is now dating John Mellencamp.
- Jennifer Garner & Ben Affleck
While moviegoers mocked Affleck's 2003 superhero turn in “Daredevil” it did lead to one of Hollywood's favorite, most down-to-earth couples. Sure, he nearly married his “Gigli” co-star Jennifer Lopez first. The two wed in the Caribbean in 2005; Garner's “Alias” TV dad, Victor Garber, officiated.
- Michelle Williams & Heath Ledger
Their onscreen marriage in 2005's “Brokeback Mountain” was a sham, since Ledger's character was in love with another man, but their real-life romance lasted three years and produced daughter Matilda. They split just one year before Ledger's untimely death in 2008.
- Angelina Jolie & Brad Pitt
The tabloids rejoiced when these two hotties teamed up for 2005's “Mr. and Mrs. Smith.” At the time, Pitt was married to Jennifer Aniston but soon enough, that marriage was over and he and Jolie have been an item ever since, globe-trotting and raising their six kids. Jolie previously married co-stars Jonny Lee Miller and Billy Bob Thornton, while Pitt had nearly walked down the aisle with “Seven” co-star Gwyneth Paltrow.
- Javier Bardem & Penelope Cruz
The two Spanish actors first met while filming the sexy comedy “Jamon, Jamon” in 1992. Their romance ignited when they re-teamed for “Vicky Cristina Barcelona” in 2007. They married in 2010, and Cruz gave birth to their second child last year. (She also had a three-year relationship with Tom Cruise after they co-starred in “Vanilla Sky.”)
- Kristen Stewart & Rob Pattinson
Twi-hards swooned when it became apparent that the passion between Bella and Edward wasn't just acting on the part of KStew and RPattz. Their relationship survived nearly the whole series, beginning with “Twilight” in 2008, only to crash and burn when Stewart was snapped kissing director Rupert Sanders in 2012. After a brief reconciliation, both have moved on.
- Ryan Reynolds & Blake Lively
Nothing good came out of the giant flop that was 2011's “The Green Lantern,” except that the two leads tied the knot shortly after. Reynolds had previously been married to Scarlett Johansson; Lively had dated Leonardo DiCaprio and “Gossip Girl” co-star Penn Badgley.
- Andrew Garfield & Emma Stone
Gotta love a man in tights: Stone and Garfield fell for each other while making 2012's “The Amazing Spider-Man” and are still together as the sequel prepares to hit theaters this May.
- Johnny Depp & Amber Heard
They got hot and heavy in 2011's “The Rum Diary,” so when they confirmed they were dating in real life, no one was very surprised. Except for the part where Heard had already come out as gay. Amend that to bisexual, because the two are now engaged, following Depp's split with long-time love Vanessa Paradis. One of Depp's exes, Winona Ryder, has called the relationship “inappropriate” since Depp is 50 and Heard is 27.