Kim Kardashian leaves the Tracy Anderson gym after a workout in Los Angeles, California on Jan 2nd, 2012. Credit:

Mom-to-be Kim Kardashian is focusing on her fitness.

After announcing she's expecting her first child with boyfriend Kanye West, Kardashian stepped out Wednesday, Jan. 2 to attend a workout class at Tracy Anderson's gym.

The reality starlet, 32, who isn't showing yet at three months pregnant, wore tight black pants and a long-sleeved top for her workout. 

West, 35, surprised his girlfriend of eight months when he revealed her pregnancy during his concert at Atlantic City's Revel Resort on Dec. 30. "Make some noise for my baby mama," he told the audience. 

Now that the news is out, Kardashian opened up to Us Weekly on New Year's Eve at Las Vegas nightclub 1OAK about how her pregnancy has been going so far.

"I have felt good. I haven't had any morning sickness, but it still isn't the easiest," she told Us. "People always say it's easy and fun. It's definitely an adjustment learning about your body and stuff like that. I've been feeling really good so that's good."

And it seems the first-time mom-to-be is taking care of her body. While leaving the gym Wednesday, she held a large water bottle in hand.