Photos taking up storage on iPhone when I have no photos Problem from iOS 10.1.1 to 10.2.1.

I have no photos at all on my iPhone yet in settings it says my photo library is taking up ~200MB of space. The number of space being taken up keeps changing constantly(in the settings app on my phone). In iTunes, the storage bar at the bottom does(when in the sync menu) not show photos.







 

What is taking up this storage, and how can I reduce it?

Troubleshooting:


I disabled iCloud photo library and iCloud photo stream, still showing the same thing.
Tried doing what @User9125 said, didn't work. I had set the date all the way back when I first got my phone, nothing showed up.
Rebooting
I had hundreds of photos in Whatsapp, I deleted them but I didn't get the storage back. It didn't even make a dent in the amount of storage being used by Photos so I don't think a third-party app could be taking up this storage.
I don't think a system app is taking this space either, because I cleared the pictures in mail and messages.
I tried using iCleaner(through sideloading) in Secure Mode and Fast Mode, but it did not clear up the photos.
There might be phantom photos still in your Photos app. Just do these things and it will solve your problem.


Go to Settings
Date &amp; Time
Untoggle "Set Automatically"
Manually change the date back. For example, today is December 10, 2016, choose something ex: like March 21, 2015. (You can change it back once we're done)
Close out of that
Open "Photos"
Select "Albums" you had already cleared out everything from the Camera Roll and "Recently Deleted" folder, But now you'll see that your "Recently Deleted" folder now has thousands of images back. Those are your phantom photos
Open it, "Select" and start deleting
Now, go back into Settings - General - Usage - Storage - Manage Storage - and you'll notice your Photo &amp; Camera is empty if you deleted everything.