By default wordpress, automatically adds the  […] to while clipping the excerpt extra data. This you will notice in the homepage when the blog posts show up.  Personally, i dont like this and i always fix this by replacing [..] to something like either remove it or with couple of dots. Here is the snippet of this code, which fixes it and you have to copy and paste it in your theme functions.php

/******************* Excerpts fix ***************/
add_filter('excerpt_more', 'new_excerpt_more');
function new_excerpt_more( $more ) {
 return '';
}