Hi
I can see how that can be a little confusing. Your service is billed for in advance, so when you're billed for Oct-Nov billing cycle (for example), you're paying for an upcoming billing cycle. However, the usage records are shown for your last billing cycle because any overages or pay per use charges will have to be on the same bill with the next billing cycle charge.
Your unbilled (current) call logs and usage information in available at myatt.com.
I hope this helps.
Thanks,
Dmitriy