Still, one fellow shopper who saw Kate browsing the beauty department tells PEOPLE: "She did look very healthy and happy, absolutely radiant. She looked like she was on a very happy planet!"
It was just two weeks ago that the royal mom enjoyed a solo shopping trip at the luxury department store in London's Knightsbridge. She bought mascara at the Clarins counter and browsed for designer dresses in Roland Mouret before attending a personal shopping appointment on the store's second floor.
Though the pregnancy could only have been in the very earliest of stages, it was apparent to everyone that the mother of Prince George was in a very happy place, indeed.
After making her Clarins purchase, Kate smiled and said a cheery "hello" to several onlookers. "She was so happy and relaxed," says a Clarins staffer who saw her being served. "If anything, it was her putting us at ease, not the other way round."
Dressed in her go-to casual outfit of skinny jeans and a sweater, with her hair casually tied back, Kate showed no signs of sickness or discomfort.
"I would never have guessed that she was pregnant, because she looked so slim, but I did notice she looked super happy – she was naturally glowing, radiant and extremely beautiful,” the onlooker says.
"She smiled at everyone. She was extremely friendly," the source adds. "She didn't look down, she smiled and looked right into your eyes – she was adorable."