Is Kourtney Kardashian expecting her fourth child?

According to a new report, the 37-year-old reality star and mother of three is currently four weeks pregnant -- and her ex-boyfiend, Scott Disick, is said to be the father.

"Kourtney has always wanted four kids, but has been adamant about not wanting multiple baby daddies," an insider explained to In Touch Weekly, revealing Kardashian's family was "shocked" by her baby news but "eventually came around to the idea."

Meanwhile, Disick is absolutely thrilled with the news.

Disick, 33, has "been doting on her and the kids [Mason, 6, Penelope, 3, and Reign, 1] ever since they found out," the source said. "This baby may even get them back together!"

Although Kardashian's alleged fourth child is said to be the baby of Disick, it wasn't too long ago that a PEOPLE Magazine source claimed she had been "hooking up on and off" with Justin Bieber "for a few months now."

"They have hooked up a few times, including recently. It happens in L.A," the source said in April. "He has met her kids, but they don't hook up around the kids. It's on nights when she has help and is able to go out."

Prior to the report, Kardashian was seen attending Bieber's concert in Los Angeles, where she labeled herself a "Belieber" after months of rumors regarding her possible romance with the 22-year-old singer.

"Kourtney is great. Justin thinks it's cool that she is older and hot. She isn't clingy and has her own life," the source continued. "There are no bad consequences for Justin to hook up with her. She is very easy going and just makes it fun for him to be around her.”

In the months since the report, Bieber has moved on from his rumored relationship with Kardashian and is now believed to be dating 21-year-old actress Nicola Peltz.

For more of Kourtney Kardashian and Scott Disick, tune into Keeping Up With the Kardashians season 12 airing on Sunday nights at 9 p.m. on the E! Network and check out a sneak peek of the upcoming episode below.

Tags: kourtney kardashian scott disick Justin Bieber