False Positive

False Positive is the third Christmas special of How I Met Your Mother.

Plot
Lily and Marshall, after attempting and failing for 2 months to get pregnant, finally manage to get a positive pregnancy test result. They immediately tell the rest of the gang, who are just as ecstatic as they are. Unfortunately, this doesn't last for long; their doctor soon tells them they're not really pregnant. Over the next three days the gang thought Lily was pregnant, and each member of the gang re-examine their own lives and react in their own unique way.

On the first night, before Marshall and Lily arrive at Ted's apartment to share the news, Ted is on the phone with Punchy, planning the floral arrangements for his wedding. Robin, overhearing their conversation, tells Ted he's ignoring his main job as best man: to stop Punchy from freaking out about the wedding. Ted defends himself by reminding her he was Marshall's best man, however Robin retaliates by recounting how he allowed Marshall to shave his head.

Ted ignores her and watches TV, realizing that Robin has recorded seven episodes of Million Dollar Heads or Tails. Robin reveals she's going to be the new currency rotation specialist on the show, or "coin flip bimbo" as Ted calls it, going against her previous plans to be a serious journalist at World Wide News and turning down a research job from them.

Barney enters, and then later Marshall and Lily arrive, sharing the news that they're pregnant. As the gang is congratulating them, Robin begins to reflect on her own life, and decides to take the World Wide News job to be a respected journalist. So the next night, when Marshall, Ted and Lily are celebrating Lily's pregnancy at MacLaren's, Robin arrives telling them she's the new WWN associate researcher.

However on the third day, when calling Alex Trebek to turn down the coin flip girl job, she gets a message from Lily saying she's not pregnant, and decides to forget about her journalist dream and take the easy coin flip job. Later that night, when the gang decided to see a movie together, Robin finds Ted outside the theater and tells him her decision to take the coin flip job.

While this was going on, Barney was having his own dilemma. Flashback to the first night, when Barney enters Ted's Apartment, he shows Ted and Robin his huge Christmas bonus check and his plans to buy a diamond suit with the money. Ted suggests giving some of the money to charity, but Barney scoffs the notion. When Marshall and Lily enter and share their news, Barney reflects on what he's doing with his life, and doesn't feel awesome.

On the second night, when the rest of the gang is in MacLaren's celebrating, Barney enters and announces "Barney's Favorite Things", to give away a bunch of free things to people at MacLaren's in an Oprah-esque manner.

Deciding he wants to do more giving, he visits Sam Gibbs at a Long Island church where he works as a minister. Sam tells him about a charity the church runs, and Barney decides to help out by writing a check donation. However, when Lily messages him telling him she's not pregnant, Barney loses his giving spirit and turns the $10,000 check into $100.00 (with a sneaky decimal point), and arrives to the movies that night wearing his diamond suit.

Meanwhile, while Robin was deciding on her new career and Barney was becoming charitable, Marshall and Lily were freaking out about having a child, and try and do everything they have to do to prepare for the baby in one night. So when, on the third night, they learn they're not pregnant, they're happy.

When they arrive at the movies to tell the gang, Ted asks why they're not devastated. They tell him they're relieved, and decide they might get a dog instead of having a baby. Ted throws his movie snack on the floor, and starts shouting at Marshall and Lily, because after all their talk about having kids, all it took was one little freak out for them to give up their desire for children, and tells them to go home and keep trying.

Ted then turns on Barney, shouting at him for wasting his money on such a stupid suit and tells him to return the suit and donate the money, by calling to the "criminals of New York" about Barney's suit causing Barney to flee. Now alone, Ted tells Robin she didn't move to New York City to give up her dreams, and forces her to call and accept WWN's research job. As Robin walks off, Punchy calls Ted and tells him he can't get married. Ted tells him he can, because he loves her, and a convinced Punchy thanks him.

Following Ted's shouting, Marshall and Lily realize they were being ridiculous, and continue trying to have a baby. Barney sells the suit and donates the money (plus dozens of suits) to Sam Gibbs's church's charity program. Robin takes the new associate research job at WWN, and later at Ted's apartment thanks him for being there to put them all back on the right track, and asks if Ted will be her best man if she ever gets married.

In the ending scene, Barney tries a Christmas message-style play on a girl called Noelle at the bar, but she turns him down.