Need Help in Understanding a confusion and Solving a problem while making Web Crawlers to get total Links Count

See more:

C#

ASP.NET

webscraping

Hi, I have tried to get a starting on making a web crawler. Was progressing well till I got this confusion That i can't understand. I have written the following code:

I am passing "http://www.google.com" as the string "URL"

public void crawlURL(string URL, string depth)
        {
            if (!checkPageHasBeenCrawled(URL))
            {
                PageContent = getURLContent(URL);
                MatchCollection matches = Regex.Matches(PageContent, "href=\"",                       RegexOptions.IgnoreCase);
                int count = matches.Count;
            }
        } 

private string getURLContent(string URL)
        {
            string content;
            HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(URL);
            request.UserAgent = "Fetching contents Data";

            WebResponse response = request.GetResponse();

            Stream stream = response.GetResponseStream();

            StreamReader reader = new StreamReader(stream);
            content = reader.ReadToEnd();

            reader.Close();
            stream.Close();
            return content;
        }

Problem:
I am trying to get all the Links of the page(http://www.google.com) but I see less count of the links from the Regex matches. It gives me links count to be 19 while when i checked the source code manually for the word "href=" it gave me 41 occurances. I can't understand why it is giving me less count of the word from the code.
Also One other problem I am currently facing is how to make sure that the links I have obtained are not broken links. They should map to some place. One way I can think of is the same way I am getting www.google.com page content by httpwebrequest object. Is thier another way or this would be the best. Thanks !!

[Edit]Code block added[/Edit]