create subdomain with cpanel

[eluser]runrun[/eluser]
Hi, today I went to Cpanel to create a subdomain, http://blog.mysite.com is the subdomain. When I enter the url into the browser, it keeps redirecting me to http://mysite.com/blog. does this have anything to do with codeigniter or my htaccess file?

If you wonder what I put in the htaccess, I do 2 things, remove the index.php. And rewrite links to http://www.mysite.com instead of http://mysite.com