PHP form submit loads blank page? - php

Question

I am aware there are a lot of questions on this regarding this issue, but I have looked through them all and none of the solutions seem to fix the issue for me. I have a form that when submitted, posts the data and it is retrieved via if(isset), as far as I know, all the syntax is correct, and the name attributes of the inputs are correct.
When I submit the form, the data in the form gets inserted into a mysql database, which works, the only issue is the blank page. Here is the php code at the top of the page and the relative html code.
PHP
<?php
require('connection.php');
if(isset($_POST['submit'])) {
$name = $_POST['name'];
$email = $_POST['email'];
$number = $_POST['number'];
$body = $_POST['message'];
try {
$stmt = $db->prepare("INSERT INTO `contact` (`c_name`, `c_email`, `c_number`, `c_body`) VALUES (:name, :email, :num, :body)");
$stmt->execute(array(':name' => $name, ':email' => $email, ':num' => $number, ':body' => $body));
return $stmt;
} catch(PDOException $e) {
echo $e->getMessage();
}
}
?>
HTML
<form method="post">
<div class="form-group">
<label for="name">Name:</label>
<input type="text" name="name" class="form-control" id="name">
</div>
<div class="form-group">
<label for="exampleInputEmail1">Email address</label>
<input type="email" name="email" class="form-control" id="exampleInputEmail1" aria-describedby="emailHelp">
<small id="emailHelp" class="form-text text-muted">We'll never share your email with anyone else.</small>
</div>
<div class="form-group">
<label for="number">Contact Number:</label>
<input type="text" name="number" class="form-control" id="number">
</div>
<div class="form-group">
<label for="message">Message:</label>
<textarea name="message" class="form-control" id="message" rows="6"></textarea>
</div>
<input type="submit" name="submit" class="btn btn-primary" />
</form>