noob question on google rankings

yeah guys im sort of new to this anyways I have my site in the first page of a search with 3m results and every browser I use shows it in a diffrent place. I tried logging off deleting history etc. Is there a good place to check the position of your page non influenced?

seoserp.com
just google "serp checker" you will get whole bunch.
I usually get that type of results when I visit too often to the site, google then decides to put it higher cause it knows i go there.

Best one in my opinion is Sescout. Remember that depending on the data center, the rankings will be different. In my experience though sescout is pretty close.