Well I'm guessing your query is in index.php because sticky posts only show up on the home page.
I've tried this before with this:
But for your query I would use multiple loops in your index.php.
example index.php: http://pastebin.com/7rncMsGa
You'll need to put this in your theme's functions.php for this to work: http://pastebin.com/15AzeFeA
Set how many posts you want to show per page in the functions code:
// set posts per page here
$posts_per_page = 6;
Change the query to what you need in index.php:
$args_loop = array(
'post_type' => array('post', 'careers-post'),
'category__in' => $page_categories,
'posts_per_page' => $posts_per_page, // required
'paged' => $paged // required
In this example all pages display 6 posts. If you have more than 6 sticky posts they will be transferred to the next page. You can also limit the number of sticky posts you want to show by changing this in functions.php:
// limit sticky posts (# number or false)
$limit_sticky_posts = false;
I've used some function from theme Twenty Twelve as an example in index.php. Replace all instances of this with your own pagination functions if you're not using Twenty Twelve:
<?php twentytwelve_content_nav( 'nav-below' ); ?>
And replace this with your own loop code:
<?php get_template_part( 'content', get_post_format() ); ?>
consider creating a child theme instead of editing your theme directly - if you upgrade the theme all your modifications will be lost.