I have a 1971 S proof penny and above the date is a little tiny W, does yours have one to? I see a speck of something on yours in the same spot as mine but pictures are too far back to tell.
1) Bad form to jump on someone else's thread with your own coin. Best to start your own. 2) Your coin is not a proof. Though it was minted in San Francisco, it is a business strike. Business strike cents were minted in SF from 1968-1974. 3) There is no "W" above the date of your coin. Check out "Pareidolia". That is most likely what you are experiencing.