You need to utilize the proper bootstrap classes. If inside a container (a true Bootstrap container), you need a row to offset the padding.
<div class="container">
<div class="row">
<header id="main_header" class="col-md-12">
<nav class="navbar navbar-default" role="navigation">
</nav>
<div class="contact pull-left">
</div>
</header>
</div>
</div>
Bootstrap has pull-left
and pull-right
already to float content. clearfix
shouldn’t be needed if you are utilizing a container/row.
Realistically you could also (or instead) use the grid utilities on the nav/contact.