First came marriage -- and now comes the baby carriage for Mariah Carey and Nick Cannon

Mariah Carey's biggest fan was on hand as the 39-year-old pop diva performed at the 15th CLSA Investors' Forum in Hong Kong on Sept. 25. "She was with her husband, Nick Cannon, and they were laughing, kissing, holding hands," says an onlooker, who caught the couple arriving at the airport. "You could tell they were newlyweds."

The onlooker couldn't help but notice something else, too: "Mariah looked great, but she seemed to have put on a few pounds. Maybe she's pregnant -- or at least planning on it!"

A friend of Mariah's says the star and Nick are definitely trying: "They've been trying their travels, and Mariah has seen her ob-gyn several times recently in California, and not just for checkups. She's talking to her doctor about pregnancy and what to expect."

Getting in mommy mode
One thing Mariah would have to change in her frenetic work schedule. She has several private appearances (similar to the one in Hong Kong) scheduled through the remainder of 2008. "She's been performing a lot lately," says the friend. "When you think about it, she hasn't been in one place for more than five days pretty much since she and Nick got married in April."

Of course, Mariah would be willing to give up all the hopping around to have a baby with Nick, says the friend. "Mariah's spent her whole life cranking out hits and working her butt off to be a top performer and singer," points out the pal. "She put aside the whole family idea -- there was never time. But things have changed; she's so in love with Nick and knows he'll be a terrific father."

Mariah didn't necessarily feel that way with her previous partners. "After her divorce from music executive Tommy Mottola in 1998, she focused on rebuilding her career without him," continues the pal. "She wasn't ready to have kids with him, nor did she want to. She was focused on work 100 percent."

Mariah also immersed herself in her career when she was dating manager-producer Mark Sudack from 2004 to 2008. "Mariah never even considered having kids with him," adds the insider. "And they were together for a long time and apparently in love."

But Mariah changed her tune when she married Nick, who, says the pal, would make a great stay-at-home dad. When Life & Style asked Mariah in May when she and Nick planned on starting a family -- and how many kids they wanted to have -- she responded, "Ha! I couldn't say anything for sure just yet, only that it's in the cards."

But she may be pregnant already, believes one Mariah insider. "She's acting differently lately," says the insider. "She went overseas, where it's easier to hide and not be seen, if indeed she's starting to show. She definitely looks different. Everyone thinks she looks pregnant. So I'm willing to say that she is!"

Still, a close friend of Nick's isn't convinced yet.

"She's not pregnant, but she and Nick are trying," the friend says. "Mariah really wants a baby, and so does Nick. So it's on the agenda for them. It's just a matter of time."

A New Year's baby?
If she's not yet expecting, Mariah hopes to get pregnant by the beginning of next year, believes the pal. "Her schedule will calm down, and she's planning on going to Aspen and St. Bart's to relax over Christmas," the pal says. "Mariah is a changed person ever since she met Nick. She has different priorities, like having a family. She's only wanted a family with someone who'd be head over heels for kids -- and she's found him in Nick."