The pop star, 35, is currently expecting her first child with Hollywood actor Orlando Bloom, 43.
She announced her pregnancy in March with the release of a music video which featured footage of her cradling a baby bump.
Perry told People magazine that currently “every day your options change and you don’t know what’s what”.
She added that she has recently emerged from a difficult period in her life.
“You feel like you’re being attacked and you can’t wake up,” she told the US publication.
“How could I have felt that so powerfully to the point where my body was seizing?
“We all have negative conversations going on in your head that can take the wheel.”
She added she now feels she has more control over her life.
“You have to take the wheel back, and I definitely did,” Perry said, adding: “I get to live life and I get to bring life into the world.
“Finding the gratitude in this pain has been a real journey, but the outcome is worth it.”
She added it took her “two-and-a-half years to find my footing”.
She said: “After being on a rocket ship and just going straight up, it was just a small change in trajectory, but it felt seismic.”
Perry, who reportedly began dating Bloom in 2016, is set to release her new album Smile on August 28.
The date was previously pushed back as the singer blamed the move on “unavoidable production delays”.