Newlywed Kelly expecting first child

The 'Motivation' hitmaker, 33, confirmed the happy news via Instagram yesterday by posting a picture of her new husband Tim Witherspoon's sports shoes alongside a matching baby pair, with the caption: "I'll be stuntin like my daddy... (sic)."

A source close to the star also confirmed she is pregnant to PEOPLE.com.

Kelly first sparked rumours she is expecting when she and her husband, who is also her manager, were spotted shopping at upmarket baby store Bel Bambini in West Hollywood last month.

An eyewitness said: "[They] checked out the furniture and strollers on the second floor and walked around downstairs."

The former Destiny's Child star, whose former bandmate and best pal Beyoncé Knowles has a two-year-old daughter, Blue Ivy, with husband Jay Z, also further fuelled speculation when she performed at the Rhythm on the River festival in Oklahoma on Saturday in an uncharacteristically baggy outfit.

Kelly and Tim got married in an intimate ceremony in Costa Rica last month.

Asked about her top-secret nuptials, she told UsMagazine.com: "Perfect. That's [all I'll say.] Perfect. Perfect day."