A pregnant woman has melted hearts online after sharing her rescue dog's precious reaction to feeling the baby kick for the first time.

Mom-of-two Heaven Leigh posted the adorable clip on TikTok (@heavenly06241127) showing Rosie's ears perk up and her tail start wagging as soon as she felt a kick. But feeling just one kick wasn't enough for Rosie, so rather than resting her head on the side of the bump, she moved to lay over the top of it instead and waited for the next one.

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Rosie started crying after she felt the baby kick, and Leigh told Newsweek she believes it was "a cry of happiness" from the rescue pup. Up until that point, Leigh wasn't sure if the dog understood the changes that were happening in her body. But following this adorable moment, she has no doubts that Rosie gets it now.

Leigh said: "I was laying down and called Rosie up to the bed, and she immediately laid down beside me and rested her head on my stomach and she felt three kicks. She's noticed the changes in my body since becoming pregnant, but I wasn't sure she knew exactly what was happening until the other day.

"With each one, it seemed like she got more of an idea what it all meant until it finally clicked. She then got up and switched to laying on top of my belly with her paws on each side, being super careful to not hurt me or baby. At that point she fully knew what was happening and what she was waiting for."

The heartfelt moment left Leigh and Rosie "both crying," and the clip has delighted millions of social media users. Since sharing the video on TikTok, Leigh has been amazed to see it generate more than 5.2 million views and over 1.1 million likes in a matter of days.

It remains unclear how much dogs understand pregnancy, and how early they can detect it, but the American Kennel Club (AKC) suggests that they will notice some changes in their owner.

With 60 times as many smell receptors as humans, dogs can pick up on the slightest changes in scent and chemical changes. So, the AKC says that a dog can most likely pick up on a change in their owner's hormones due to pregnancy, but they probably won't know what it means.

How Did Social Media React?

Leigh was so thankful to have captured this sweet moment between Rosie and her soon-to-be baby brother. As the baby continued to kick, Rosie couldn't help but "wag her tail with excitement."

The social media reaction to the video has been incredible, and Leigh has loved seeing so much love and support for Rosie.

"TikTok has always been an outlet for me, and I wanted others to be able to witness the love that animals can have for their humans, even before they've met them," Leigh told Newsweek.

"I never expected it to go as viral as it has, but I'm beyond grateful it did. It makes me beyond happy seeing the effect Rosie's had on others and the amount of smiles she's brought to so many faces."

The video has earned plenty of attention online since going viral, with many people praising Rosie for her reaction to the baby bump. Among the 1,600 comments on TikTok, one person wrote: "Oh she loves her tiny hooman already."

Another TikToker responded: "Even dogs know there's a little human baby in there."

While another comment reads: "We honestly don't deserve the love dogs have for us."

Do you have funny and adorable videos or pictures of your pet you want to share? Send them to life@newsweek.com with some details about your best friend and they could appear in our Pet of the Week lineup.