This is a bit like going to the police and admitting you murdered someone, then thinking twice about it. Probably a little late. However, you probably wanted to get a permit anyway, since doing a highly visible project like building a deck is not likely to escape notice, and doing so without a permit can lead to all sorts of long term problems. As previously poster noted, go to the inspector, tell them what you did, file for the permit (you are going to need plans), and ask them what you can do to make it right. The average building inspector is not likely to give you a hard time, they will probably find a way to work with you and get it approved.
I started a deck last September, filed for a permit, and am still working on it. I stopped by three times to discuss various issues with the inspector (use of lag screws vs bolts, depth of footing when I hit a rock, method of attachment of ledger to house). The inspector told me to take pictures of the holes I dug, he would come out to visit when the deck was complete. I guess he liked that I stopped in to see him, so he did not feel the need to verify depth of hole.
