The 37-year-old, who welcomed her second child Jameson on 26 December, shared a selfie of herself working out in the gym.
She told fans she weighs 160 pounds (72kg) at 5’3”, writing on the photo on 2 April: “By ‘regular standards’ that makes me obese.
“I know I’m not at my goal or anywhere near it after baby two but dammit I don’t feel obese.”
The mum-of-two continued: “The only thing I’m feeling is myself. Stay off that scale ladies!”
She used the hashtags #feelingmyself #strongismygoal and #bodygoals.
Mums were comforted by the fact Pink wasn’t putting pressure on herself and her post-baby body.
“So thankful for this,” commented one mum. “Had my last baby at 38 and I am the same weight. But honestly finally feel like a woman. Even though it’s the biggest I have ever been. I’m learning to accept it but stay healthy.”
Another commented: “You have no idea how much I needed to see this today. I’m battling with the numbers after giving birth to baby number three.
“Need to remember it’s about how I feel not what I weigh.”
The singer has resonated with new mums previously by calling herself “completely normal” for having not lost weight six weeks after giving birth.
“Day 1, let’s do this,” she wrote at the time. “Week six post-baby and I haven’t lost any weight yet.”
But rather than worry she was behind with her workouts, she added: “Yay me, I’m normal!”
As well as baby Jameson, Pink is also mum to five-year-old Willow with her husband Carey Hart.