Its repeating my menu items

<?php
				$args = array(
					'theme_location'  => '',
					'menu'            => 'main_menu',
					'container'       => false,
					'container_class' => '',
					'container_id'    => '',
					'menu_class'      => '',
					'menu_id'         => '',
					'echo'            => true,
					'fallback_cb'     => 'wp_page_menu',
					'before'          => '',
					'after'           => '',
					'link_before'     => '',
					'link_after'      => '',
					'items_wrap'      => '<ul id="header-menu">%3$s</ul>',
					'depth'           => 0,
					'walker'          => ''
				);

				wp_nav_menu($args);
			?>

I am using this code to fetch menu,
but its repeating it twice.
like home about services home about services

Thanks