Data usage

I am coming from an Android device so I understand the concept of data usage. Just switched to the Iphone last Friday. Previously I used between 1 and 2 GB of data a month. I have set up the Iphone much the same way and haven't used the phone any more than before. In the past week Verizon and the Iphone shows that I have used 2GB. Don't get the overage. Now some questions. I use Wifi now a great deal of the time which I never used on the Android, so I thought that would even lower the usage. What could be using so much data? Does the notification center constantly use data to stay in real time such as weather and stocks? I have two e mail accounts and have them set to push. However, on 1 I only get maybe two or three messages a week and have that set to push under the advanced tab and the other set to manual under the advanced tab so I don't think that accounts for the usage. Any ideas what is using all the data? Thanks for any help.

 

I am actually on Verizon. This is what I thought too but I did log into Verizon and it shows the same thing. Also, I do not use Icloud so that could not account for the usage.