Funny, I'm going through the same thing! But I've been eyeing this crap like a hawk:
I have been pulling my reports TWICE A MONTH from CreditReport.com - Free credit reports and credit scores
. I see my score in flux each time. And this is from all three bureaus, experian, equifax, transunion. If I pull all of my archived reports, I can see that sometimes (and quite often habitually with some creditors), the reporting is not on-time. So a payment isn't necessarily reflected for the same month!
What I just found out, though, is that there are about 71 different "credit scores" for your credit profile with each bureau. So you could go to a Mercedes dealer and your pulled score will be different than the mortgage company's pulled score. This is because they pay each bureau a different price for pulling a particular score. Some creditors pay the cheapest for the higher score while others, like apartment managers, charge the consumer a fee to pull a report showing a lower score (although the lower score is probably more in-depth).
Granted, the FICO is the most commonly-known score, but that's just one version of your score. There are other scores out there for your report, and they aren't FICO scores, but most people think they are.
All I know is that when I check my reports all the time, it doesn't affect my score, because I'm checking my own credit. I think creditreport.com is one of the few sites that can make this happen.