the rating for the blog post was changed from 4* to 5*
Hence 2 points for 4* rating got reduced while 5 point for 5* rating got added = 3 points
Further I can see that a helpful answer was removed and another discussion was marked as correct answer. this explains 5 points
you can find this info in your reputation tab in section Expertise by turning the cards:
Yasemin ULUTURK's Profile | SCN
Further you can see that the discussion Re: Not able to do left outer join which shows 5 points for you in your reputation has no more a helpful answer.