Katy Perry has encouraged Halsey to enjoy every stage of her pregnancy because her body's gearing up to "perform a real miracle".

Halsey took to Instagram on Thursday to share a series of photos of herself and the foods she's been eating, as she reflected on her journey to motherhood so far.

"February is the shortest month, but the days seem like they are taking very long. Butttttt also going so fast?!" she began her caption. "I've been thinking lots about my body. it's strange to watch yourself change so quickly. I thought pregnancy would give me very strong, binary feelings about 'womanhood' but truly it has leveled my perception of gender entirely (sic)."

Halsey continued, "My sensitivity to my body has made me hyper aware of my humanness and that's all. Doing a remarkable thing. And it's grand. I hope the feeling lasts. I cook a lot, sleep even more, and read lotssss of books. I miss my family. And you guys too! bye for now (sic)."

She then added in a comment, "I thought there would be a lot of expectation or pressure on me to wake up everyday feeling like some 'girly-girly fertility goddess', but instead I wake up and eat when I'm hungry, sleep when I'm tired, and focus on growing a human. And that is all I expect myself to do. Liberating (sic)!"

The singer, who is expecting the baby with her boyfriend Alev Aydin, was flooded with messages of support from her followers, including Perry, who became a first-time mum to daughter Daisy in August.

"You're about to perform a real miracle, get that rest and just be! I love you!" the Firework hitmaker remarked.

Halsey went public with her pregnancy in late January.