Bootstrap navbar logo overlay - html

Question

I have a navbar in bootstrap that has the links and a logo in the center. The navbar stretches to fit the logo image, I'd rather have the logo overlap the navbar. Here is my code, I actually used a base someone already made yet it still doesn't work.
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<div class="navbar-collapse collapse w-100 dual-collapse2 order-1 order-md-0">
<ul class="navbar-nav ml-auto text-center">
<li class="nav-item active">
<a class="nav-link" href="#">Link</a>
</li>
</ul>
</div>
<div class="mx-auto my-2 order-0 order-md-1 position-relative">
<a class="mx-auto" href="#">
<img src="http://placehold.it/120/ccff00" class="rounded-circle" height="120" width="120">
</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target=".dual-collapse2">
<span class="navbar-toggler-icon"></span>
</button>
</div>
<div class="navbar-collapse collapse w-100 dual-collapse2 order-2 order-md-2">
<ul class="navbar-nav mr-auto text-center">
<li class="nav-item">
<a class="nav-link" href="#">Link</a>
</li>
</ul>
</div>
</nav>
CSS
#media (min-width: 992px) {
.navbar {
height:50px;
}
}