When Joey writes Monica a check for $2000, it takes less than five seconds from the time he puts his checkbook on the counter to start writing the check to the time he hands Monica a folded check.
Phoebe mentions that this will be her first time living with a male. Even though she lived with Gary for a brief time in an earlier season, she most likely didn't want to mention her previous relationships in case they would damage her current relationship with Mike.
It has been made clear for the entirety of the series that Joey owes Chandler a LOT of money from various loans (for headshots, acting lessons, etc) and covering bills when they lived together. For Chandler to ask Joey for a "loan" now is absurd. If Joey has enough money to "loan" Monica and Chandler a total of $4,000, it should've just been payback for Joey's debt to Chandler.
When Chandler walks into his apartment and says, "Ah Perfection," there is a boom mic visible.
Chandler should know Monica wouldn't be spending their limited money for a breast augmentation.
Monica shouldn't be worried about Chandler not being comfortable with her body changing when she's pregnant because they've already been trying to get pregnant therefore he obviously accepted the fact her body will change, furthermore his acceptance of her body changing has already been addressed in The One with the Nap Partners.
Chandler thinks Joey only has only baking soda and beer in his refrigerator but didn't consider there's baby formula and baby food for Emma.