Halsey was "treated like a teen mom" during her pregnancy.
The 26-year-old star gave birth to a baby boy called Ender on July 14, but admits she found it difficult being pregnant while living her life in the public eye.
Halsey - who has Ender with her screenwriter boyfriend Alev Aydin - shared: "I'm 26, and I tried very hard for this pregnancy and it was like, I'm financially independent, I'm pretty far along in my career, it feels like the right time for me to do it. And I got treated like a teen mom a lot of the times.
"Where people were like, 'Oh my God, you're so young, and you have so much to do in your career, and you're not married and you're this.' And it triggered all of these feelings of shame from when I was younger. It triggered a lot of old feelings of shame in me where I was like, how can you have an opinion, that kind of opinion on me making this decision?"
Halsey also thinks the same people would have been critical of her if she'd delayed starting a family until later in her career.
During an interview with Zane Lowe on New Music Daily on Apple Music 1, she said: "There's also, 'She worked too hard, she never had a family. She's going to die alone. She was too obsessed with work, she never found someone. It's a shame she's not going to have any kids, her career's not going to hold her at night.'
"OK. So nothing. So f*** 'em and I just was like, I'm going to do what I want to do. You know what I mean? I was like, this is important to me."