Perry also took to Twitter to share her relief that the news was out there.
"Omg so glad I don’t have to suck it in anymore," she wrote before adding, "or carry around a big purse lol."
Although she hasn't revealed how far along she is, Perry did explain that she needed to announce soon because it was getting increasingly hard to hide.
“I had to reveal it at some point. It’s getting pretty obvious.”
The couple have yet to announce wedding plans but Perry recently said the marriage was more important than the ceremony.
"I call myself a 'bridechilla' as opposed to a bridezilla," Perry told Australia's Stellar magazine. "Orlando and I are united with our approach. It’s not about the party, it’s about the coming together of people who will hold us accountable when things get really hard. Because it’s really great and then it’s really hard. Those are just the facts when you’re with someone who challenges you to be your best self."