Heidi Montag may not be as ready for kids as she previously thought.

'The Hills' Star Holly Montag Is Pregnant, Sister Heidi Wants To Be Next

Although Heidi has been begging husband Spencer Pratt for a baby for months on WEtv's Marriage Boot Camp, her sister Holly's pregnancy struggles may have made the reality star change her mind about her plans for a family.

"I was like, 'I think I can put this off for a little bit because you look REALLY uncomfortable!'" Heidi explained to Us Weekly. "I was like, 'I'm three years younger. Maybe I can wait three more years to catch up.'"

Spencer Pratt Lost His Mind During 'The Hills,' But Says 'It's Almost Back'

At the end of last year, Holly announced she and her husband, Richie Wilson, were expecting their first child together. In the months since, Heidi has spent tons of time with her sister, and is currently planning her baby shower.

Around the time of Holly's announcement, Heidi told In Touch Weekly she wanted to be pregnant by the end of 2015, and said she'd prefer to have either two boys, or a boy and a girl, since boys are "easier."

"She is miserable!" Pratt added of Holly's pregnancy.

However, he's not convinced Holly's misery has swayed Heidi to put off having children.

"Heidi is such a bluffer," he alleged. "She'll see a baby commercial and be like, 'Oh, look at those diapers!'"

For now, Heidi is excited to continue on with her sister's pregnancy journey.

"She was just out here and she's super pregnant," Montag said. "So, I'm going to go home this weekend."

Tags: Heidi Montag Spencer Pratt The Hills MTV Reality TV