Display posts of the last 7 days

<?php $args_post = array(
  'posts_per_page' => 3,
  'post_status'    => array('publish'),
  'orderby'        => 'rand',
  'date_query'     => array(
    'after'     => '1 week ago',
  )
);
$query_post = new WP_Query( $args_post );