The Sorry singer shared a picture of a sonogram on social media on Monday, and after fans accused him of pulling a prank he shared snaps of model Hailey cradling her stomach while surrounded by medical professionals and wrote, "If U thought it was April Fools."
He later revealed it was all a joke by posting an edited sonogram picture which featured a puppy at the centre and told fans, "Wait omg (oh my God) is that a,,, APRIL FOOLS."
The prank didn't go down well with some fans, who scolded Justin for being insensitive to those who suffer from infertility issues.
"As a woman that can't have children I find this disgusting and disrespectful," one user wrote in the comments, while another added, "These jokes aren't funny... do you understand how many families have to deal with infertility and loss of pregnancy? Shame on you."
"Honestly people would die to become parents, I hate the 'I'm pregnant' April Fools," a third wrote. "Let's hope you and your wife aren't infertile so you don't feel the heartbreak of not being able to carry your own child. Just coming from a place of experience."
Ruth Bender Atik, spokesperson for The Miscarriage Association, told Standard Online: "I don't suppose Justin thought for a moment that it might cause upset. Hopefully, any comments that are made will make him more aware of the sensitivities of pregnancy loss and infertility."
Some of Justin's celebrity followers didn't fall for the joke, with talk show host Ellen DeGeneres commenting, "@JustinBieber, if you're April Fooling me, so help you," and reality star Kris Jenner adding, "Ugh I actually got chills.... I almost cried then I realised what day it is."
Even Hailey, who tied the knot with Justin last year (18), made it clear she wasn't particularly amused by sarcastically commenting, "Very funny..."
The pregnancy prank comes just weeks after Justin wrote a note to fans explaining that he wanted to focus on himself and put his music on hold so that he can "be the father I want to be".