10 More Annoying Mistakes You Never Noticed In Friends
3. Rachel's Extremely Long Pregnancy
We first discovered that Rachel was pregnant during Monica and Chandler's wedding, which Monica had earlier stated was on May 15th (in Season 7 in "The One With The Cheap Wedding Dress). However by the time Halloween comes around in Season 8 in "The One With The Halloween Party", Rachel is wearing a skin tight dress claiming she wants to use it before she gets too big for it due to the pregnancy. As someone who must be at least six months at the time, she is showing no signs.
Later in the season, in "The One Where Rachel Is Late" her due date is said to be a week before the premiere of Joey's WWI movie. He earlier said that this was on Memorial Day, so May 25th. This means that Rachel must have been pregnant for over a year.