There may be coding error, For example - Open Sans" is the font that is imported. But you can replace it with yours. If it is a single word font, just include the font name after the family=... if it is two words, do as I did and add a + sign between each word.
NOTE: Place @import at the very first line of the CSS file.
If you need complete control over how the fonts are loaded. Most browsers will defer painting the content to the screen until all of the CSS is downloaded and applied - this avoids the "flash of unstyled content" problem. The downside is... you may have an extra pause and delay until the content is visible. With the JS loader, you can define how and when the fonts become visible.. for example, you can even fade them in after the original content is painted on the screen.
Once again, the 90% case is the <link> tag: use a good CDN and the fonts will come down quick and even more likely, be served out of the cache.