January JonesJanuary Jones is one of the newest Hollywood sweethearts to show off her pregnancy style.

The 'Mad Men' star donned a modest midnight blue and black dress for the premiere of 'X-Men: First Class' last night. She stepped out in New York City, subtly showing off her growing belly. The criss-cross under her bust gives the slightest highlight to her bump, and the off the shoulder neckline adds the tiniest bit of sex appeal.

Jones joins the vast number of celebs showing off their baby bellies. Fellow mommy-to-be, Natalie Portman, made her way through award season this winter, finding dress after dress to make her tummy the topic of conversation.

Although Jones' bump is still barely there, it certainly continues to get a lot of chatter. She announced she was pregnant in April, and has yet to reveal who the father is.

Looks like her style won't be the only thing discussed as her pregnancy progresses.