For most mothers, the first day of school for their children is an emotional day that they are eager to be a part of. Unfortunately for Kate Middleton, the expecting mom was forced to miss her son’s first experience in school due to something out of her control.

On Thursday, a source told Us Weekly that the Duchess of Cambridge was not happy that she could not be with Prince George for his first day of school due to her severe morning sickness, a condition known as hyperemesis gravidarum.

“Kate watched the news from home,” an insider told the media outlet.

“She was desperately sad that she couldn’t make it but she is on firm bed rest now until she feels better,” the insider close to the royal couple added.

Prince William and Prince George Prince William took Prince George to his first day of school. The father and son are pictured outside of Kensington Palace on Sept. 7, 2017 in London, England Photo: Getty Images

Although Middleton couldn’t make it due to her acute morning sickness, Prince William was by his son’s side and held his hand as they walked into Thomas Battersea’s school in London. The royal reportedly stayed with his son until he was settled into his classroom.

During his time in school, the young prince will not receive any perks just because he lives in a palace. “Our aim for him, as well as for all of our pupils, is to provide a safe and secure and happy environment where he feels supported by a kind and loving community,” Ben Thomas, the headmaster of Thomas’s Battersea said.

“That’s all we will be trying to achieve for him. There won’t be any special treatment at all. In fact what his parents would like for him, as any parent would like for their child, is they have a wonderful, fulfilling and private childhood in a place which is secure,” he added.

In March, the school, which was attended by both Prince Harry and Prince William, released a statement welcoming Prince George to the institution.

“We are honored that the aims and values of Thomas’ reflect those that their Royal Highnesses would like for Prince George’s education. We are deeply conscious of the trust that they, like all Thomas’ parents, are placing in us and we hope very much to live up to their expectations,” Thomas said at the time.

Missing Prince George’s special moment was tough on Middleton. “The first day of a child’s school is always a bittersweet day for a mother,” the source said.

“Both Kate and William are extremely proud of George and how well behaved he was as he arrived, but it’s also a little frightening to see him grow up this fast!”

While Prince George was busy attending his first day of school, his mother, who has visits with her doctor every day, was confined to her bed. Middleton’s mother has actually been staying with the family in order to help her daughter out and support her. “Carole is Kate’s rock in tough situations like this. Mother always knows best!” the source added.

While the Duchess of Cambridge has experienced the hyperemesis gravidarum while pregnant with both George and Charlotte, she was eventually able to return to her daily activities and royal duties. It shouldn’t be long until the royal is back to making headlines everywhere for her incredible taste in fashion and her chic maternity wear choices.

Kate Middleton Kate Middleton was not happy about missing her son’s first day of school. Catherine, Duchess of Cambridge is pictured attending the Last Post ceremony on July 30, 2017 in Ypres, Belgium. Photo: Getty Images