Catherine, Duchess of Cambridge attends day 4 of the Cheltenham Festival on Gold Cup Day at Cheltenham racecourse on March 15, 2013 in London, England. Credit: Samir Hussein/

Kate Middleton definitely has that pregnancy glow! The Duchess of Cambridge stepped out with husband Prince William on Friday, March 15 to attend the Cheltenham Festival at Cheltenham Racecourse in the English countryside.

The royal couple, both 30, who are expecting their first child together in July, were all smiles as they arrived at the horse races together. Mom-to-be Middleton looked as stunning as ever in a salmon-colored Joseph coat, Stuart Weitzman Zipkin boots and her favorite Lock & Co Betty Boop hat, which she's worn on previous outings. Her husband looked dapper in a navy suit and red tie, and carried his winter coat over his arm.

"Kate walked close to him," says an onlooker tells Us Weekly of the expectant royal. "They both look really great."

The dad-to-be told Cheltenham's local Echo newspaper that he was looking forward to watching the races. 

"I've got some money riding on Africa Gold although I can't remember which race it's running in," he said. "I love coming to Cheltenham as I've got friends here and I've always loved racing."

For more on Middleton's pregnancy -- and the cute nickname she and Prince William have given their baby-to-be -- pick up the new Us Weekly, on stands Friday.