Bootstrap 4 pin to top navbar element - html

Question

I'm using bootstrap 4.1 navbar here. I want my div "#pin_to_top" to be always at the top of the navbar. So that on wider screens it is
Logo - Menu - "#pin_to_top" (all on the same row)
and on smaller devices it is like
Logo - "#pin_to_top#
Menu (menu is under my logo and div)
Also any other piece of advice about my code would be much appreciated :)
.navbar-brand img {
height: 2rem;
}
.phonecall {
border-radius: 2rem;
background-color: #28a745;
font-weight: bold;
}
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" rel="stylesheet"/>
<nav class="navbar navbar-light bg-light d-flex flex-column flex-md-row navbar-expand">
<a class="navbar-brand" href="#">
<p>LOGO</p>
</a>
<div class="d-flex">
<ul class="navbar-nav flex-fill pl-md-5 text-nowrap">
<li class="nav-item "><a class="nav-link" href="#">Menu1</a></li>
<li class="nav-item "><a class="nav-link" href="#">Menu2</a></li>
<li class="nav-item "><a class="nav-link" href="#">Menu3</a></li>
<li class="nav-item "><a class="nav-link" href="#">Menu4</a></li>
</ul>
</div>
<div id="pin_to_top" class="ml-auto d-flex flex-column flex-md-row align-self-start" >
<div class="p-2">
<a class="">Some info here</a>
</div>
<div class="navbar-text text-nowrap phonecall px-2">
<a class="text-white" href="tel:[phone]">[phone]</a>
</div>
</div>
</nav>

Answer 1

Bootstrap 4 includes a fixed-top class to solve your problem. ;)

Answer 2

you should give position fix to your class and give this top:0;

Answer 3

use position absolute for parent and add some css for a good design on small screen
#include media-breakpoint-up(md) {
div#pin_to_top {
position: absolute;
left: auto;
right: 0px;
}
}