Wifi issue iOS 6

I have a grandfathered unlimited AT&T plan for my iPad3, and I recently updated to iOS 6 on the release date and made sure to reset my cellular data usage. I am at almost 8GB now and I have not changed my usage at all - normally I would be around 2GB halfway into the billing cycle.

I also noticed when I'm at home my device will say I'm on LTE, but when I do a speed test I'm clearly on Wi-fi because the upload speeds are still low compared to LTE, and I've turned off the LTE and wifi to confirm each's speeds. Do you think that when the iPad says i'm on LTE at home it's counting it under my Cellular Usage even though it's really coming off my Wi-fi at that point? I don't see any other way I have used to much data in only 2 weeks!!!