Under Cellular Data, check the number next to Current Period. If you want to check when the current period for your iPhone data usage tracking began, scroll to the bottom of the screen.

Data can cost you big bucks if you're not paying attention. This article explains how to check data usage directly from an iPhone or Android phone or through a major carrier, such as AT&T, Verizon ...

3. Data Usage is High . Your data usage should not suddenly and unexpectedly spike. If it does, it could be a major sign that someone else is using your phone without your knowledge and sending ...