Professional BMX rider Corey popped the question to the former The Hills star in November (15), and weeks later, the couple announced it was expecting its first child.

Audrina, 31, has been imminent motherhood with wedding planning, and although she has an idea of the kind of ceremony she wants, she has put some aspects of the big day, like dress shopping, on hold until after she gives birth.

"It's a little overwhelming," she tells Fit Pregnancy and Baby magazine. "After I have the baby, I have no idea what size my breasts will be or if my hips will go down or get bigger. So for now dress shopping, at least, is on hold."

"I didn't want to rush getting married because stress is bad for the baby," she continues, revealing her fiance convinced her there was no need to hurry to the altar before their tot's arrival.

"Corey said, 'Stop caring what people think. Their opinions don't matter,'" the mother-to-be recalls. "Anyway, we've already been together for so long, it's like we're already married. It's just a title at this point - and a ring."

Audrina has yet to share details about where or when they are thinking of exchanging vows, but there is one thing that is certain - none of her The Hills castmates will be in attendance at the intimate affair.

Meanwhile, the star admits she is really enjoying life as an expectant mum, and although she barely suffered any morning sickness, she was struck down by severe fatigue early on in the pregnancy.

"There were three or four days during my first trimester when I could not get out of bed and all I wanted to do was sleep," she confesses. "But overall, I'm feeling good!"

"Watching my body transform has been amazing," she adds. "I feel like a woman now."

But fans have been warned not to touch her baby bump uninvited: "I'm already super-protective of (the baby)," she says. "This guy at the airport asked if he could take a picture with me and put his hand right on my stomach. I was like, 'Please, don't touch!'"

And, as Audrina nears her due date, she is making sure her hospital bag is ready, so she can make a dash as soon as she feels her baby coming.

"I'm definitely delivering in a hospital," she explains. "I've had friends who've gone without drugs and they've said it's super painful but they'd never do it any other way. Meanwhile, my sister Casey, who has two kids, had an epidural both times and she made childbirth look easy. I'm not sure which route I want to take yet. Either way, I'm a little scared.

"All I know is, the moment I feel my first contraction, I'm going to the doctor. I want to be in the hospital bed, relaxing, with my lavender-oil diffuser set up."