The couple dropped a potential clue while visiting an event in November to show their support for military wives and families whose partners are deployed overseas.
While chatting to one such wife, Harry may have hinted he and Meghan are planning on giving Archie a sibling.
Susie Stringfellow, mother-of-two, revealed the Prince asked her what it was like to have a second baby.
She told Forces Network: “Harry was really quite interested in how things were with second children as well because we both have older children.
READ MORE: Princess Eugenie pregnant? Royal baby news on the horizon – MAJOR clue