Kelis is reportedly in "amazing spirits" over her second pregnancy.
The 36-year-old singer appeared to confirm she is expecting another baby when she performed at the Afropunk Festival in Brooklyn, New York, with a visible bump over the weekend.
Although she hasn't officially spoken out about the news, the star is said to be thrilled about becoming a mother again.
"She is really excited about her pregnancy," a source told E! News. "She has a great support system from her family and friends. She is in really amazing spirits."
Multiple insiders have confirmed the news to the outlet.
Kelis wore a hot pink maxi-dress when she took to the stage, and was seen cradling her growing stomach as she sang. At the moment it's not known when she will give birth, but she is thought to be well into her pregnancy.
"She had a great time at Afropunk this weekend and will continue to perform as long as she feels good," one source said, with another adding: "She is several months along and feeling great."
Kelis is already mother to six-year-old son Knight, who she has with her ex-husband Nas. The couple married in 2005 after being engaged for around a year, but she filed for divorce when she was seven months pregnant.
The father of her new baby isn't known, although a year ago she was seen strolling around Venice Beach in California with a hunky mystery man.
Last year, the star gave a hint that she would be open to having more children when she spoke about how inspiring she finds kids.
“I feel like with a lot of women who were pregnant, it’s usually my favourite album of theirs, which I don’t realise until after… I mean, you’re literally full of life,” she mused to fuse.tv.
“I’m generally comfortable in my own skin and I really do love being a mother. I think it comes across in the writing because you can’t really ignore it, you know?”