1.5GB of data in two days... what gives?

After moving over from Sprint to AT&T for the Lumia 920 some how I've used 1.5GB of data in 2 days.. On Sprint it would take me half a month to go through that much data.. anyone else having this problem? I'm not doing anything differently on my L920 compared to my Sprint phone...

Update: After speaking to a AT&T CSR she informed me my data usage online at attDOTcom was completely off. She said something is wrong with their system. I dialed *3282# from my phone and it gave me the correct usage amount.