Links showing in custom menu that should not be

Hello all. Having strange issue.

I am developing on my local machine and cannot provide a link so I will try to be very descriptive.

I am creating a child theme from twentyfourteen.

I have created a custom header menu. The only link I have added to the menu so far is a page called “About Us” but the Blog, and Home page links are appearing in the menu and at the moment it should only have “About us”.

I named the menu “header” and I added the following to header.php:

<?php wp_nav_menu(array('theme_location' => 'header', 'menu_class' => 'header-main')) ?>

in nav-menus.php on the back end the menu structure is only showing “About Us” and I have the auto add pages checkbox unchecked.

Why are the Blog, and Home links showing, and how can I remove them so that only my custom links will show?