Need help with pagination

                $paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
                $args_blog = array(
                'post_type' => 'post',
                'paged' => $paged,
                'posts_per_page' =>  get_option('posts_per_page ')
                );
                $query_blog = new WP_Query( $args_blog );
                if($query_blog->have_posts()) : while($query_blog->have_posts()) : $query_blog->the_post();

                 $big = 999999999; // need an unlikely integer
                 echo paginate_links( array(
                'base' => str_replace( $big, '%#%', esc_url( get_pagenum_link( $big ) ) ),
                'format' => '?paged=%#%',
                'current' => max( 1, get_query_var('paged') ),
                'prev_text'          => __('Prev'),
                'next_text'          => __('Next'),
                'total' => $query_blog->max_num_pages
            ) );