We would have expected Kim Kardashian and Kanye West's bundle of joy to show up fashionably late. But the little guy is already turning the tables on us.According to a tweet from the reality star , her due date is likely to arrive a bit earlier than originally anticipated."Went to the Dr today for a check up, guess I was off on my 20 week mark by a week or two," Kardashian shared today. "But not the 20 lbs LOL."When the pregnancy was made public, North West's new sibling was slated to arrive around Christmas of this year. But from the sound of this tweet, he's likely to show up around Thanksgiving instead. It also seems as though the mama-to-be is ready to get this show on the road."I'm gonna keep it real: For me, pregnancy is the worst experience of my life!" Kardashian wrote in a post , titled "From the Desk Of: How I Really Feel About Being Pregnant," on her personal website last month. "Maybe it's the swelling, the backaches, or just the complete mindfuck of how your body expands and nothing fits," she went on. "I just always feel like I'm not in my own skin."So, let the baby countdown and delivery-date betting pools begin!