"Hello little grandchild, it is me", the famed architect wrote. The photos show different angles of her pregnancy bump with the caption, "from about 27 wks time flew". I love you both so freaking much.
The speculation comes days after Gigi's sister had fans convinced the model and singer had welcomed their daughter when she posted a photograph of her standing next to her older sibling both in which they both cradle their "baby" bumps.
Gigi Hadid is showing off her baby bump!
While appearing on his show The Tonight Show Starring Jimmy Fallon via video link, Gigi said: "Obviously, we wished we could have announced it on our own terms but we're very excited and happy and grateful for everyone's well wishes and support".
"I loved it, I knew what I wanted from the pics and Gab and L&I really made it happen for me but was definitely more tiring than working normally", she wrote.
One follower commented below to ask whether this meant Gigi had given birth, to which Mr Hadid replied: "no, not yet", shortly before deleting his post altogether.
The model shared a photo on Instagram on Tuesday, which was taken three months ago on June 11, in which she poses with her elder sister Gigi. I cried the tear because I know, my heart would always belong to you, ' he finished before signing off. Two buns in the oven except mine is from my burger and Gigi's is from [Zayn].
Gigi and Zayn are yet to confirm the news personally, but why the heck else would Mohamed be writing a heartfelt letter to his grandchild?
According to Gigi's mom Yolanda Hadid, the supermodel was expected to give birth 'sometime in September'.
"Right now I just want to experience it and I write in my journal a lot and I just don't want to worry about waking up every day and look cute and post something", she continued.