Fans weren't fooled as the image that he posted was traced back to Google Images and is one of the first results under the search term "ultrasound".
But the pop star wasn't done making fans scratch their heads.
"U thought it was April fools" he captioned the post.
While Kris Jenner commented, 'Ugh I actually got chills.
Stunning his 107million Instagram followers yesterday with a scan pic, the 25-year-old sent his fans into a frenzy.
The third photo really revealed the prank: a clearly fake sonogram pic with a cute puppy photoshopped inside! The accompanying caption reads, "Wait omg is that a, APRIL FOOLS".
Don't get it scrambled, girl. He expected her to laugh, "but she cried". "Pregnancy is not an April Fool's Joke".
"I do have sympathy for women struggling from infertility".
Prince Harrys ‘biggest fan dies at 99
Congratulations on reaching this important and impressive milestone before your centenary year next year. Prince Harry first met Ms Dunne in 2015 when he noticed her husband's war medals pinned to her chest.
Ty Dolla $ign was one of the first celebrities to comment on the post.
Another added: "I hope you never have to feel the heartbreak that comes with sitting on the bathroom floor staring at a negative pregnancy test over and over again".
Of course, we assume that Justin meant no ill-will by his April Fool's prank but, given how serious pregnancy is to millions of people all around the world, it's understandable why people are taking issue with the joke. But I will apologize anyway and take responsibility and say sorry to people who were offended.
Bieber then likened the unintentional outcome of his prank to that of shoving birthday cake in his little sister's face.
Justin was quick to mention that he was in no way comparing the cake in the face thing with the struggles some people go through to get pregnant, as to avoid even more unnecessary backlash.
'Some might have laughed but some were offended.
"Of course justin bieber will think a pregnancy announcement would be amusing on April fools. esp so when 1 in 7 women have had a miscarriage. not to mention those suffering from infertility", wrote one Twitter user.
Was this just a simple joke that people took too seriously?