Now it is July and this has been more than a week, so I think it can not be a fluctuation which generally occurs when Big G make changes in its algorithm.

Because I did notice heavy fluctuation in my website ranking on Google but all settles down within a week but that too was one by one keyword.

Now I think you should revise your changes if you made some just before this ranking change.
If you are working more than enough on link building than you should give gaps in it and do it naturally don't do overwhelming.

All The Best!