1st Lager help

Ive got about 6 ales behind me, and I figure I'd try my hand at a lager.
I brewed 6 days ago, and put the brew in a converted freezer/fermentation chamber at 54-55 degrees (optimal for my yeast strain) . For the 1st 4 days, it was bubbling vigorously. Last night when I checked - dead. No bubbles. I pulled a sample this morning and had a SG of 1.006 down from an OG of 1.045 - 86% apparent attenuation.
I used Wyeast Urquell Lager 2001 which has an avg attenuation of 74%. Why the high attenuation?
Can primary be done so quickly? Have I missed my chance for a diacetyl rest?
What should I do now? Warm it up for a few days before crashing it, or have I missed the boat?

Thanks for any and all help!

Long story short, I wouldn't worry about it. Yes, you can have it go crazy on the sugar and finish things off way faster than you might anticipate (and yeah, that's pretty fast . You could just have gotten a particularly voracious batch of yeast, or conditions were just perfect, or any number of random variables.

I'd proceed as you planned with a rest and crash, but I'd probably leave it for a few more days just to give it a chance to mellow a bit and make sure everything's wrapped up. Check again in 3-4 days and see if the gravity has moved a bit; if not, go ahead and move on with your rest and then crash as planned. Lager away, and enjoy!

Awesome! Thanks for the help!

+1 to the above. I had a couple of lagers hit FG while I wasn't watching. Just warm them up a bit so they can clean up, I like to let them have 2 weeks in primary before racking / crashing / lagering.

Did you brew all grain? If so, what was your mash temp? If you mashed in the 140's you may have had very fermentable wort.

I mashed at 130 for 15 min then brought it up to 150 for an hour. It came down to 148 by the time I drained and sparged. I had a stuck sparge for the second running, so it sat around longer than I had wanted, as I had to stir it and let it resettle. I had originally brought up the temp to 170, but with all the stirring and waiting it dropped into the mid 160's before all was said and done. I missed my preboil SG - Target was 1.040, I got 1.032.

Follow up question - I'm fermenting in a Fast Ferment conical. I am going to keep it at 55 degrees for another 3-4 days as recommended by smagee and then will bring it up to 70 for a rest for 2 days. After that is it ok to transfer to a keg, cold crash and let it lager in the keg till it's done, or should I keep it in the conical? I don't want to tie up the FF for that long.

thanks again to all the input. There is sooo much to learn....

Take a sample and taste it, you may not even need a diacetyl rest. I mainly brew lagers and haven't needed a rest yet.