Britney & Kevin's Baby Adventure

Newlyweds and Britney and Kevin: Chaotic stars Spears and Federline are having fun as they settle into their new shared role: parents-to-be. The couple recently spent a two-week vacation in Scottsdale, Ariz., getting spa treatments, shopping and, most important, going to restaurants. As Britney puts it: "Eating for two is so much fun. I get to eat lots and lots."

"It's like my own therapy," Spears says of Chaotic, the six-part reality series that started May 17 on UPN. The show – a compilation of home movies – documents their globe-spanning romance, starting with their first encounter in a Hollywood club last year and ending with their surprise September nuptials. "The craziest things I've ever done have always (turned out) for the best," says Spears.

Spears, who is due in the fall, tested her mommy skills in Santa Monica over Mother's Day weekend with Kori, Federline's 2-year-old daughter with ex-girlfriend Shar Jackson. "She talks about Kori nonstop," says the singer's cousin Laura Lynne Covington, "and every time I see her she always has new pictures to show me. She's always loved children."

On April 12, Spears let fans in on her secret: "The time has finally come to share our wonderful news that we're expecting our first child together." The announcement on her Web site came amid tabloid reports that she had been rushed to a hospital because of bleeding. But according to a source, "It was a minor scare. She was fine."

Spears (on April 7 in Florida) made no secret of her plans for a baby, telling PEOPLE last year, "I want to be a young mom. ... I can see us as parents. Next year at 23, I am so there." And this spring, her bulging belly began raising eyebrows.

The newlyweds, who joined Spears's mom Lynne in Florida for a vacation on April 7 (left), have the grandma-to-be's approval. Of Federline, Lynne has said: "He's calm, easygoing, and he laughs a lot."

Besides Spears's curvier figure (with Federline in Beverly Hills in March), there were plenty of clues about the couple's intentions. Writing on her Web site in November, Spears said, "The only thing I haven't done so far is experience the closest thing to God and that's having a baby. I can't wait!"

Federline, at a March photo shoot for Details (left), will be a busy dad: The former backup dancer – who has two kids from his relationship with Jackson – plans to act, produce music and launch a fashion line. "I have a bunch of different ideas for jeans, sport jackets and shirts," he says. "It would be the rock and roll side of cool dress-up clothes."

Spears took a solo shopping trip to Santa Monica boutique Babystyle in January, where she reportedly browsed through the store's trendy maternity wear. At the time, though, the singer walked out with only a purchase for stepdaughter Kori, 2.

Spears says she loves the "little ones" and has extended those feelings to Federline's children, playing stepmom to Kori (in Malibu in September) and Kaleb, 8 months, whose mom is actress Shar Jackson. "Britney adores Kori," says her assistant Felicity Culotta. "She talks to her in baby talk and she just gets the giggles and says, 'You're funny!' "

With her Chihuahua Bitbit close to her heart, Spears indulged her maternal instincts and loaded up on Christmas gifts (in November) for her stepfamily. But she didn't forget Bitbit – she also picked up a little crib for the pup, who with maltese Lacy helped start the Spears-Federline clan.

Spears and Federline (in Stockholm last April) have been nearly inseparable since their whirlwind romance took off last spring during her European tour. It was on the trip from Ireland to New York that Britney popped the question – only to have Kevin say no, then turn around and ask her to marry him. "And I said yes, of course," she told PEOPLE.

The two made their first official appearance as newlyweds at the Billboard Music Awards on Dec. 8, but since coupling up, Spears has kept a lower profile. "I want to enjoy the simple things that I missed over the past few years due to working way too much," she told fans last fall.

Federline has gotten the thumbs up from both Britney's dad Jamie (left, in November) and mom Lynne (in July), who called the couple "a good fit." Family is a priority for Spears: The singer expressed interest in building a house behind her mom's in Kentwood, La., once she starts a family.

A month after their surprise September wedding, Spears and Federline got lei'ed in Fiji, where they spent a 10-day honeymoon at a $1,975-a-night beach bungalow. The exclusive Turtle Island resort offered a private beach and lomi-lomi massage, said to release emotional stress and encourage harmony between the body, mind and soul.

"It's when I'm happiest that I have a problem with junk food," Spears has said. And since she's been with Federline, the singer has often been snapped munching on Cheetos, Pop Tarts and curly fries (in October, left). Most recently she had a craving for Wendy's, loading up on chili, a baked potato and a chicken sandwich.

A week before their Sept. 18 wedding, the couple snuggled close while shopping for bedding in Malibu. Spears said it was all part of a greater plan: "I'm redecorating a lot of things because when we decide to start a family, everything needs to be perfecto!"

"Being married is great, and I can't wait to start my family!" Spears (leaving her surprise wedding ceremony) said in an October message to fans. Her in-laws are just as excited. "We are all about grandkids," Federline's dad, Mike, told PEOPLE. "I hope they have four or five."