She looks pretty pregnant here. Since Erik99559 says this is from the last day of the legislature, the photo was taken on or about April 13, 2008. She gave birth on April 18th.
TeacherRefPoet may be right, I may well end up with egg on my face. So be it.
I still have questions.
Update 1: And now suddenly one of the bump pictures is dated 2007. Is the scrub in progress?
Update 2: Track Palin, the governor’s oldest son, went away to basic training in late September 2007, so that would make this picture from sometime prior to that, wouldn’t it? However, this picture is missing Track. Townhall says it’s from 2006. Track would have been 17 and presumably still in high school, yet unavailable for a family photo? And Piper, the youngest Palin daughter, would have been 5. There is no 5-year-old in that photo. This must have been taken after September 18, 2007. But when?
Update 3: And now the picture in question has a date of 2006. Did the ADN take the picture or was it supplied by the family? I still don’t see a 5-year-old in the photo, but whatever.
Update 4: And now we’re back at it. Here she is on March 14, 2008. Here she is less than 30 days later. Yeah, that doesn’t happen. Thank you, “Kind“.
Update 5: And now Bristol is officially pregnant.
The Kos diarist ArcXIX has found a good one.

Here’s Governor Palin seven-months pregnant with Trig, the baby she delivered in April of this year.

Here’s Sarah Palin pregnant with son Track in 1989. Clearly, shes in her third trimester.
ArcXIX has also got some great pictures of Bristol holding Trig. Of course those don’t mean anything by themselves, but it makes for interesting imagry. The type you find on the cover of a tabloid in the checkout stand.
The McCain plumbers are going to have their hands full.
Update: Jack Bog is on to something here.
Here’s a guy from Alaska who’s just as mystified as to why McCain chose Palin as I am. With all three “gates” (bridge, trooper, and baby) lighting up the Interwebs (I’m having a heckuva Sunday for traffic, tyvm), the McCain campaign is finally sending a team up to Alaska to find out what exactly it is they’ve purchased in Sarah Barracuda.
But now the cleanup crew has started. Palin’s praise of the Obama energy plan that was on her website? Scrubbed. Photos on the website during the time period she was supposedly to have been pregnant? Allegedly scrubbed too. John McCain’s organized vetting team? Supposedly on their way to Alaska right now. (Note to McCain staffers: Vet FIRST…it works out better that way.) The National Enquirer? Supposedly all over this already. Photos of the pregnant (or not) Palin are circulating everywhere. One thing is certain, the rumor mill has started, and there’s no getting this toothpaste back in the tube.
The toothpaste analogy is spot on and I think ultimately the Palin episode will be able to pull together all the different narratives about McCain’s judgment and his propensity to shoot from the hip. McCain is in a major bind here though; if the team finds any merit to any of the accusations and he has to jettison Palin, there will be Hell to pay with the base. If, on the other hand, they find nothing, it won’t stop The Enquirer or other investigative reporters from continuing to look into all of this. For example, who, if anyone, was Bristol dating around the time she may or may not have conceived? You think The Enquirer won’t find him? You think The Enquirer won’t be looking for a birth certificate? They found the one for John Edwards’ alleged love child, they can find Trig Palin’s. Jack Bog’s insurance question will need to be answered as well. The Palin’s are covered by the state, yes?
Good luck to the McCain plumbers. They’re gonna need it.