Frankel reluctantly confirmed the news after gossip blogger Perez Hilton reported the 38-year-old -- who had also just confirmed her October 8 engagement to Jason Hoppy over the weekend -- was pregnant on Monday morning.
"It's premature to be telling people this," Frankel, who is less than two months pregnant, toldPeople as she reportedly fought back tears.
"It's not the way I wanted it to get out. I haven't even gone through my first trimester. We haven't even heard the heartbeat. My [fiance's] parents didn't even know."
Frankel said she and Hoppy, who she has been dating for eleven months, are "both so excited."
"I am praying everything is okay but I don't know that yet," she added.
Frankel told People the couple plans to get married before the baby is born.
"Because of my age, it's not like I was going to meet a boy, and then be engaged for a year and then be married for a year before we started trying [to have kids] ... I'd be 45." she said.
"I'm no spring chicken. I didn't think it was going to happen right away. Because of my age, sometimes we weren't totally careful."
According to Frankel, the last few months have been "like [winning] the Triple Crown."
"I got engaged, we got pregnant and we're gonna get married. It's a miracle," she told People. "I got to be honest, we are both feeling kind of proud of ourselves. We are both 38 and we were like, 'Listen, your fish can swim and I am fertile.' So that's exciting."
Earlier this month, Bravo announced Frankel -- who also finished as the first runner-up on The Apprentice: Martha Stewart in 2005 -- will star a new reality series that will focus on her love life and career as a natural foods chef. Despite reports to the contrary, Frankel has insisted she will also remain part of The Real Housewives of New York City's third-season cast.