Also, your method requires users to make a minimum of two requests to the server just to receive some useful content. This will be a problem if your pages are visited very frequently because some users might feel like they may be stuck on the loading screen forever while the server is trying hard to fulfill the second request to other users.
To see what I mean visually, go to http://www.webpagetest.org/ and run your page through it and see how other web browsers load it.
If you really have to have some sort of loading indicator, try to do it without requiring another request, otherwise search engines will think your site is slow.
Also, run your page with google's page-speed insights to see what they think as well.