Pregnant Alessandra Ambrosio Reveals: "It's a Boy!"

Alessandra Ambrosio revealed that she and her fiancé Jamie Mazur are expecting a baby boy! The Victoria's Secret stunner took to her Facebook to share the happy news, posting a photo of herself with the baby announcement written in the sand.

OK! GALLERY: PREGNANT ALESSANDRA AMBROSIO TAKES HER BUMP SHOPPING 

"We really tried to keep it a surprise but we were too anxious," she wrote. "Soon, we will have a little boy to rock our world!" 

"I have wanted a boy for a long time," Alessandra tells E! Online. "I actually thought my first baby was going to be a boy, but then, of course, was very happy to get a girl. But now I am getting a boy as well, it's absolutely perfect. It's the best news."

Alessandra is only five weeks away from delivery, but admits she and Jamie have yet to decide on a name for their unborn son.

"I have five good names for a girl and really none for a boy," she reveals. "I want something that works well in both Portuguese and English. It can't be too American or my grandmother won't be able to pronounce it!"

OK! NEWS: OK!'S DIET CONFESSIONS WITH ALESSANDRA AMBROSIO 

Alessandra and Jamie are already the parents to three-year-old Anja, who is thrilled about becoming a big sister. 

"Anja is telling everyone how happy she is," Alessandra says. "I love having a girl, she's super fun. She's really excited and has also come up with a name she would like him to be called. I told her that her name for him can be his nickname."