I've created a custom metric called loadtime:

Here is how I'm creating the session:
ga('create', analyticsCode,{ 'cookieDomain': 'test'});
I'm sending it to analytics like this:
var timeDiff = Math.round((Date.now() - initialTime) / 1000);
ga('set', { 'loadtime': timeDfff });
ga('send', 'pageview');
I'm getting the pageview information, but when I try to create a report to check my custom metric, I see no information. I've been trying to send this information for the past 3 days, so the analytics delay can't be the problem.
What am I doing wrong here? It is a Single Page Application, so that's why I'm sending my own page load time.
Thanks