I don't know what you have connected to your modem, but one possibility is various program updates can vary greatly in size from month to month. For instance Microsoft releases their big updates on the 2nd Tuesday of the month, but sometimes they also release updates on the 4th Tuesday of the month. Also wonder if you get the same amount of email every month with the same accumulated size of attachments.
Hello Donna, In addition to what JEP suggested, we can take a look at what data has been used on your account. If you email us at firstname.lastname@example.org we can review your account and see how your data is being used, if things are updating in the background, how many devices are connected, ect.
An excede rep mentioned to me the increase in websites using animated flash ads and content. This can use up data. Facebook for instance defaults to running videos automatically. I learned you can turn off this feature on FB and other sites so video only runs if you choose to view it.
That's a good reply Mini. But, like so many replies that mention a solution, you provided no information on how to go about performing the operation. That makes the info provided almost useless. Thanks, at least we can spend a lot of time trying to figure out how to do it. That will probably use up as much data allowance as having a unwanted running video.
For those who are interested, you can stop Facebook from autoplaying videos by going to Settings from the dropdown menu in the upper right, then Videos on the lower left of the next screen. There should be a setting to turn autoplay on and off. You can also change video quality to save data.