I have been very busy over the past several days and have not checked on my accounts. However today I pulled up my adsense account and was very confused. I normally make something every day but for some reason over the past 4 days I have made nothing. I have had page views and even a few clicks but earned nothing. Can anyone tell me why this might be?

They might be invalid clicks. Or PSA.

You may have public service ads. These dont pay.

I some times have similar thinks. Not all clicks do count. I sometimes receive x clicks, only the first m worth $ and the rest, x-m worth $0

In the last week, I noticed a drop in the $$ for my clicks, but maybe it's just me & you. I'm not sure.