Blue Ivy Carter may not be a "Single Lady" forever.

At the Met Gala in New York City Monday, new mom Beyonce Knowles, 30, said she and husband Jay-Z, 42, have talked about expanding their brood. "I definitely want to have more," Knowles told Entertainment Tonight. "I don't know how many. God knows. I don't know yet."

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Just don't expect a pregnancy announcement in the near future. "I don't know about soon!" Knowles giggled.

The singer -- who is currently rehearsing for a special three-night engagement over Memorial Day Weekend at Revel Beach's Ovation Hall in Atlantic City, New Jersey -- added that she has "such a full life. I feel like now I know the reason that I was born."

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Knowles said she's "been working really hard" to get her post-baby back. "There are no secrets. [It takes] discipline!"

She's not kidding. The 16-time Grammy Award winner works out five days a week with trainer Marco Borges. "We do cardio and plyometric moves like lunges and jumps on and off a bench," the pro recently told Us Weekly.

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Knowles, who is 5-foot-9, avoids processed fare and sticks to whole foods like vegetables and grilled meats. "You don't have to eat only celery sticks," Borges advised. "Be sensible and exercise constantly."

This article originally appeared on Beyonce: I "Definitely" Want to Have More Kids With Jay-Z