How Tori Spelling Told Her Husband About Baby No. 3

By Ulrica Wihlborg

04/12/2011 at 04:25 PM EDT

Tori Spelling wanted to tell husband Dean McDermott that she was pregnant in a special way – and as fate would have it, the timing worked out just right.

"I found out on Valentine's Day," Spelling, 37, tells PEOPLE. "It was perfect timing."

How did she deliver the news? "I wrapped up the pregnancy test in a box and bow and gave it to Dean as his Valentine's Day gift," she says. "He was beyond surprised. Best gift ever!"

As for how she's physically feeling this time around, Spelling – who is already mom to son Liam, 4, and daughter Stella, 2 – says she's been "much sicker this pregnancy" than during her past two.

PHOTOS: The Spelling-McDermotts Family Photo Album

"I have been nauseous for the past three months straight," says the Tori & Dean: sTORIbook Weddings star. "Thankfully it is starting to get better now."

Son Liam, who has seen his mom pregnant before, was onto the news before she even told him about it. "Liam kept saying, 'Your belly is getting huge. That means there's a baby in there,' " says Spelling.

When she and McDermott, 44, finally did tell their kids the news, "They were really excited," says Spelling. "Now they are obsessed with telling people, 'My Mommy has a baby in her belly!' "