SQLite and PHP register system not working

This is my registration code using PHP and SQLite. It keeps going to the statement "user already exists" when it certainly does not. I check to see if the username is greater than one in the database (if it exists) and it does not, but if I echo out the count it always says its equal to one...

$checkUser = $db->prepare('
    SELECT COUNT(*) 
    FROM users
    WHERE 
    user = ?
');

$checkUser->setFetchMode(PDO::FETCH_ASSOC);
$checkUser->execute(array($user));


$numrows = count($checkUser);

if ($numrows == 0) {

    try {

        $reg = $db->prepare("
            INSERT
            INTO users
            (user, pass, email)
            VALUES
            ('$user', '$pass', '$email')  
        ");

        $reg->setFetchMode(PDO::FETCH_ASSOC);
        $reg->execute();

    } catch (PDOException $e) {
        print_r($e->getMessage());
    }

    echo ('success...');
}
else {


    die ('user already exists');
}