Credit: Jeff Vespa/

It's every bride's nightmare!

Though her wedding to Joel Madden is just one day away, Nicole Richie still hasn't settled on the perfect gown.

"She's deciding between two dresses: Marchesa and vintage Chanel," a Richie pal tells the latest Us Weekly (on newsstands now).

But before Richie exchanges vows with her beau of four years, the former reality star (and mom to Harlow, 2, and Sparrow, 1) jetted to New York City on December 3 for her final fitting at Marchesa.

"Nicole brought her stylist Simone Harouche with her," a source tells Us. A lot of thought went into her dress -- it was a priority for her."

Meanwhile, preparations for the winter-themed ceremony were already under way back in Beverly Hills. As tables and chairs were delivered to her dad Lionel Richie's estate, planner Mindy Weiss began inviting the couple's closest pals to the December 11 affair.

"Mindy called all of the guests personally," a pal tells Us. "It's going to be a very small wedding."

For more on Nicole and Joel's wedding -- including which A-list stars made the final guest list -- pick up the new Us Weekly, out today!