April 5, 2012 at 8:40 AM ET
Tori Spelling loves a good surprise.
Just five months after welcoming daughter Hattie, the 38-year-old announced she's expecting her fourth child this fall. (Husband Dean McDermott, 45, is also father to son Jack, 13, from a previous marriage.)
"All my friends keep asking me (if it was planned) and I'm like, 'Seriously? Hattie was one month old. Do you think it was planned?'" Spelling said at her "CelabraTori" book launch in NYC Tuesday. "I was up all night with feedings."
She added: "The doctor said, 'Wait six weeks (to have sex),' and Dean was like, 'They tell everyone that.' We didn't wait that long with Stella or Liam. I was like, 'Well, I don't want him to think that the sex is going downhill,' so now we're on baby No. 4."
The Oxygen reality star joked that daughter Hattie, nearly 6 months, "had a lot to say" about getting a younger sibling. "She was up in arms. She tossed that paci right out the door. Furious."
Liam, 5, and Stella, 3, were "over-the-moon and super excited" when Spelling and McDermott announced Hattie would be coming into the world, but with their new sibling, due this September, "it was as if we had said, 'Oh we got milk today. We brought home milk today and put it in the fridge and you can go help yourself to a glass.'"
Since first becoming a mother in 2007, Spelling has adapted the way she parents her children. "I learned I'm a little too lenient and I'm good cop when I should be bad cop sometimes," she said. "What I like best about myself as a mom is the fact that I'm still kind of a kid at heart. I didn't know that side of me would come out."