To check how often your keywords are used in your page, use the Google search engine to search for your keywords. Next, click on the highlighting tool in the Google Toolbar. It looks like the tip of a highlighting pen. This will highlight the keywords you used in your last Google search.
Finally, type the URL of your website in the browser window. You don't have to follow a link for the keywords to be highlighted.
Look at your web page. Do you see the keywords highlighted often, or are they sparsely populating your page? Do they appear frequently in at least the first paragraph? If you find that your keywords are not used frequently, consider revising your web page or focusing on different keywords.