"Woke up to thousands of texts about all the pregnancy news this morning. I want you to hear it all directly from me," she wrote on Twitter Tuesday.
The "Simple Life" star revealed the news on her iHeartRadio show "This is Paris."
"I am not pregnant, not yet. I am waiting until after the wedding. My dress is being made right now so I want to make sure it looks gorgeous and fits perfectly so definitely waiting for that part," Hilton confirmed.
"The only thing in the oven at the moment is my Sliving Lasagna!" she said referencing her new cooking show on YouTube, "Cooking with Paris."
Hilton, 40, and Reum, also 40, got engaged in February after dating for a year. "I am excited about this next chapter and having such a supportive partner," Hilton told Vogue at the time. "Our relationship is one of equals. We make each other better people. He was absolutely worth the wait!"
"When you find your soulmate, you don’t just know it. You feel it," she wrote on Instagram when she made her engagement announcement. "My love and I have been together since our first date and for my birthday, he arranged a special trip to a tropical paradise. As we walked to dinner along the beach, Carter led us to a cabana adorned with flowers and dropped to one knee. I said yes, yes to forever. There’s no one I’d rather spend forever with."
The international DJ did reveal they plan to start a family at some point. She said in January on the "Trend Reporter" podcast that she's been undergoing IVF treatments.
"He’s just my dream guy. … [Carter is] 100 per cent [the one]," Hilton gushed. "We talk about [planning a wedding] all the time and planning our baby’s names and all of that."
"I'm really excited to just move on for the next step of my life, and finally just have like a real life," she added. "We have been doing the IVF, so I can pick twins if I like. Kim [Kardashian] is actually the one who told me about that. I didn't even know anything about it."