Be kind to yourself and do this to avoid embarrassment later -
HIT the URL - https://www.google.com/history/
If all is good, ‘No Thanks’ should be already selected.
ELSE refer below image (select the Remove all Web History link) -
Further details are here - http://howto.cnet.com/how-to-remove-your-google-web-history/8301-11310_39-57382925-285.html