I had 73 points for coming 2nd in one of only 3 tournaments of the 39 I entered that  have finished.

The total points has gone up to 83, but have had no notification of why.

How can I find out where the other 10 have come from?

if you placed like 15th in a tournament of 100 for example, you would probably get 10 points.

You probably got something like 10-20th in the other 2 tournaemnts

The recent one to finish i came 6 of 12.

Could that be the 10 points?

Yes. http://www.chess.com/tournaments/players.html?sortby=standings&id=14297

#6	NimzoMal (1990)  (10 points awarded)

Thank you