The original post that Bieber uploaded was a captionless screenshot of an ultrasound.
But the Love Yourself singer later revealed it was all a hoax, replacing the baby on the scan with a little puppy as a playful April Fools.
A few people pointed out that joking about a pregnancy is no laughing matter to those struggling with fertility issues.
Here are a few of the unimpressed reactions in the comments: 'Don't worry it's just April fools right?' / 'Is this supposed to be amusing?' / 'Lame a** joke.' / 'These kinds of jokes ain't amusing.' / 'You should name it April.
Biebs isn't the only star who's gotten heat for joking about conception.
Don't get it scrambled, girl. He apologised to the ones who were offended by his posts.
So, no, you don't get a free pass to post about being pregnant for the April Fools' Day attention, or to possibly make a statement.
Users were upset with his disregard for people who struggle with fertility and his lack of sensitivity to a very hard situation. My April Fools prank was in no way meant to offend women who struggle with that. In his latest Instagram post he wrote, "I was unhappy last tour and I don't deserve that and you don't deserve that, you pay money to come and have a lively energetic fun light and I was unable emotionally to give you that near the end of the tour".
Another added: "It better won't be an April fools cuz I'm crying hard ok".
"Justin Bieber joking about Hayley being pregnant is soooooo insensitive considering there's so many women out there that can not get pregnant or have lost children", a social media user tweeted. While some congratulated him, others thought he was pranking them. You sometimes just don't know what will hurt someone's feelings not to compare pregnancy with cake in the face but it's just to paint the picture of not knowing what will offend.
'Some might have laughed but some were offended. Think before you prank on April Fools Day, because pregnancy is not a joke.
But the joke hasn't gone down well with some people.