Analytic implemented after Google penguin was introduced.

[IntegratedS]

I have confusion, that whether my site was hit by Google penguin or not because my site keywords are facing a major drop since the penguin was launched. But I do not know how to track this because Google analytic was implemented on May 2nd 2012 and this algorithm was updated on 19th and 24th April 2012.
Please give your valuable suggestions.
Thanks