Kim Kardashian was left fuming Monday after she was congratulated for being pregnant. The only problem: her older sister Kourtney is the one expecting.

Some people just can’t Keep Up With Those Kardashians! The 29-year-old reality star was leaving a doctor’s appointment in Downtown L.A. yesterday afternoon when she had the encounter with a less than informed fan.

“Some woman just came up to me & said congrats 4 being pregnant! I know she thought I was Kourt but rude! Do I look 8 months preggo?” Kim moaned on Twitter Monday.