I was shocked when friends flocked to congratulate me after posting a simple selfie — can you spot the optical illusion?

It’s all about the angles.

Rebecca Mcgonigle, from the United Kingdom, was confused when her followers kept commenting congratulations underneath her recent Instagram photo. That’s when she realized she unintentionally created an optical illusion with a bad pose that made people think she was showing off her new baby.

“I thought, ‘What the f–k?’ and wasn’t sure whether to delete it, but I thought I’d keep it up because it’s funny,” Mcgonigle, 25, told Kennedy News and Media.

The PhD student, who studies chemistry, received a text from a friend alerting her that people thought she was posing with a newborn.

“I love you so much right, but [in] your Instagram post I thought your knee was a baby’s head and your skirt looks like a blanket. I did a double take and it really made me laugh,” the text read.

In the photo posted on Apr. 14, Mcgonigle was inside her room sitting down with one knee cap exposed and the other covered in her white skirt.

“The lighting was good so I thought I’d take a photo to post on social media and I just didn’t realize,” the young woman admitted.

Mcgonigle’s pose created an optical illusion that gave off the perception that one knee was a baby’s head and the other looked like the newborn’s body covered in a blanket.

“People were seriously asking if I’d had a baby and that was strange to reply to,” she added.

Mcgonigle received a flood of celebratory messages and considered removing the post to eliminate more confusion.

“Girl congrats,” wrote one person. “Motherhood suits [you] so much girl.”

“Congratulations on the new addition, do they have a name?” questioned a follower.

“I thought you were with child” added a jokester.

“Omg I thought you were holding a newborn but it’s your knee,” commented another.

Mcgonigle revealed the overflow of reactions was hilarious.

“I wasn’t embarrassed by it because it was funny and my boyfriend just thought, what the f–k is going on?” she chuckled.

The not-expecting mother was relieved that her friends had noticed the illusion before family members saw the photo.

“I’m glad my family didn’t see it first and panic,” she shared.

Eventually, the Glasgow, Scotland resident added a comment underneath her post to clear the air “I AM NOT WITH CHILD, THAT’S A KNEE.”