The full background check usually isnt complete until after you have started OCS. At least that's what I've come to understand between here and usnavyocs.com. They begin the check and if any major red flags come up that could also be holding you up.
If you had to get any medical waivers or there is the possibility of anything in your background that is questionable, there's your hold up.
As far as planning for OCS, my plan is to wait until I get my final select letter and orders for OCS then tying up the loose ends. I.e. rent, taking care of bills, getting all banking in order, storing all of the junk you wont need now. My suggestion is to have a plan of how much time you think you will need for that, then when you get your orders and final select stuff apply it to a working calendar. I'm hoping to quit my job about 3 weeks before my report date to get everything in order, and PT like a mad man...
I'll be there around that same time frame, good luck, keep pushing