Credit: Frazer Harrison/Getty

Don't tell Don Draper!

January Jones is pregnant. Her rep tells Us Weekly that the Mad Men star "is happy to announce that she is expecting her first child this fall."

The 33-year-old actress dated Saturday Night Live's  Jason Sudeikis, 35, from July 2010 until January 2011. Other notable ex-boyfriends? Singer Josh Groban and Ashton Kutcher.

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Jones is keeping the details of her pregnancy private, including the identify of her unborn baby's father.