Hilary Duff is a busy mom-to-be. The former Disney star, who is more than four months pregnant, is positively glowing as she promotes her second novel, "Devoted," which hits bookstores Tuesday (October 11).

The book is a supernatural tale about love, destiny and adventure and picks up right where she left off in her first book, "Elixir." The best-selling author isn't just busy writing the third installment of her book series; she's also gearing up to be a first-time mom. And other than the lack of sleep the past few months, pregnancy has been a smooth ride so far.

"I feel really good. It's been pretty easy, and I haven't gotten sick at all, and I don't have too many cravings," Duff told MTV News. "It's so different. It's literally like an alien has taken over your body. One day I'll have a good day, and one day I'll have a bad day, and it kinda goes like that."

The former "Lizzie McGuire" star is eagerly awaiting the news of the sex of her baby, but she's holding out for two special people to be there to share in her excitement.

"I can already find out, but I want my mom and my sister to be there, but they've both been out of town. When they are both in the same city and we're all there, then we'll find out," Duff said.

We're not sure Duff can wait much longer. "I'm going crazy! Pregnancy is kind of boring. There's not too much you can do, so those dates are very important to you, so you count down."

What does Duff think she and professional hockey player husband Mike Comrie will be having?

"Everyone else says it's a girl, but I think it's a boy," Duff said. "I'd be happy with a girl, but my sister's like, 'You can't keep saying that, because then when it's a girl, everyone's gonna be like, 'You really wanted a boy!' I don't care what I get, but every time I think about it or dream about it, I see a boy."

Duff, who plans to "take a break" from having kids after her pregnancy, is now on to the hardest part: picking out a name.

"If we give the baby kind of a unique name, we need to give it a normal middle name in case it hates it and wants to like fit in better and then maybe we just need to go totally traditional," Duff said. "And we're like, 'How can we be naming it before we even see it?' There's so much to think about!"

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