Fertile times in the Zolciak-Biermann household!

Just 10 months after giving birth to son KJ, Kim Zolciak is pregnant with her fourth child, several sources close to the Real Housewives of Atlanta star confirm to Us Weekly.

PHOTOS: See Kim's over-the-top wedding dress

Zolciak, 33, and husband, Atlanta Falcons player Kroy Biermann, welcomed little KJ in June 2010. The reality star has two older daughters -- Brielle, 15, and Ariana, 9 -- from previous relationships.

PHOTOS: Real Housewives hubbies hall of fame

On Twitter Tuesday, after announcing the big news, the "Tardy for the Party" singer thanked her daughters and "all our friends for keeping our pregnancy a secret u guys are the best!"

She added: "Thank you for all the Congrats! We feel so blessed!"

PHOTOS: Biggest reality show bombshells ever

After meeting at an Atlanta fundraiser in fall 2010 (in an encounter shown on an episode of the Bravo hit) she and Biermann, 26, tied the knot in November 2011.

Get more Us! Follow us on Twitter, Friend us on Facebook, Subscribe to Us Weekly