"Katy is dealing with the nerves of being a first-time parent, and Orlando is stressing about having a baby in their lives at this time."
Despite the pressure on their relationship, the source added Perry is delighted about becoming a mother for the first time.
"[She] is overjoyed and elated this she is pregnant," the source said.
Perry and Bloom got engaged in February 2019. He has a son, Flynn, 9, with his ex-wife Miranda Kerr.
The pop star shared in an interview with Ryan Seacrest shortly after she shared her pregnancy news that there was "a lot of friction" between her and Bloom.
Perry revealed the gender of her baby on Instagram recently, sharing a photo of Bloom's face covered in pink icing.
"It's a girl," her caption read.
According to the Mail Online, reports claim Perry will name her child after her grandmother Ann Pearl Hudson, who died just weeks after she shared her pregnancy joy with her fans.
She first shared she was having a child in March in the video for her single Never Worn White.