While in the company of the Danish Crown Prince and his wife at a United Nations aid depot in Copenhagen on Wednesday, center officials offered the royal couple a cake with peanut paste, a staple of UNICEF packages handed out in areas suffering from famine.
And while William and the Danish royals enjoyed the treat, the Duchess of Cambridge politely refused.
Adding to the speculation, Kate reportedly gave Prince William a knowing look.
What is more, the usually discrete Palace reacted to the incident.
“Her spokesman went out of their way to stress that she has no nut allergy whatsoever,” Duncan Larcombe, royal editor for The Sun, told ABC News.
If the pregnancy is confirmed, it would be great news for Kate and William, who have been under pressure for a baby since their marriage in April.