Yep, I get my oil tested as well. I could VERY easily go to 12k+ miles if I wanted to. But I choose to have the oil go though one hot/cold season so it's usually 7-9 months which in my case ends up being 6-9k miles. For those of you who are changing synthetic oil every 3k you're wasting your money.. a lot of money. You might as well wait til 6k and send in your oil to get tested, you'll find that you've still got a TON of life left in your oil. Our engines just aren't that hard on oil when running properly.
I'd recommend changing your oil at the earliest (assuming it's a daily driver that's running well) at 7500 miles. Even at this point it's mainly to change the oil filter and not the oil. Get the oil tested, see if you have high particulate matter, if you don't go higher. I know I can run a little bit longer due to my oversided oil filter however, though it doens't hurt that I've also gotten my oil tested. Think it out, the oil test costs $20. You save that much by not changing the oil once. I'm going 3x longer than some of you... You do the math.
