learn what does minus negative balance mean on adsense

last night when i check my adsense balance i have seen a minus (-) before my total adsense balance, that was like (-$47.97usd) so usually i got worried and instantly I've mailed to Google to know what actually happens to my adsense

So Google replied me and after reading their reply i got my Happiness back

This is Google team reply
Hi,

Thanks for your patience. we have verified that the issue affecting your account affects only the displaying of your earnings, so your earnings will be paid as usual after you've reached your payments threshold. In the meantime, you can view an estimate of your monthly earn by visiting your report page.
Our engineers are working as quickly as they can to investigate this issue and we hope to have a fix soon. Thank you for your patience in the meantime!
Sincerely,

My Final Words
where Google said its a bug so its a bug, It is the home page only that shows this problem, your earning will not be affected by this so don't worry if you see a minus (-) on total adsense balance,
Its a known bug and not a problem; not sure if fixed yet, but it does not affect your earnings.