My earnings were extremely low today and so I went to find out what was the cause. I browsed my site incognito to see ads that are only available to guests and I noticed my highest paying ad is missing! So I go straight to the "My Ads" section on Adsense and the Ad Unit is completely gone....My site is completely up to standard with Google Policies and all. They didn't send any email about the ad or anything.

What do you think caused this???