HI!
I'm 10 days away myself and tried to check in. No luck. i emailed customer service and they assured me everything was ok with my reservations, but their site is brand new and they are working on that issue.
this is what they sent me:
"My Disney Experience is in it's infancy stages and we are currently
working to fix all known errors. Thank you for bringing this issue to
our attention. Please be assured I will be sending your account
information along to the appropriate department.
For online check in, please go to mydisneyreservation.com. Here you can
complete your online check in process and you should also be able to
access your reservation details. When you have completed the online
check in process, simply click on the "Walt Disney World" logo in the
top right corner. As long as the words "Walt Disney World" are in blue
and green, this will direct you to the original website. If you have
trouble accessing that please call our Internet Help Desk at (407)
939-7765. We are open 7 days a week, 7:00AM to 11:00PM eastern time."
i haven't tried yet, but hopefully it'll work