Over the past couple months, many Google Now users on Android have been complaining that their Google Now cards are not always loading due to an error that says “no internet connection.”
There is a bunch of threads about this, here is one that keeps popping up in the Google Web Search Help forum.
Here is a screen shot:
The fix seems to be reinstalling the app. The issue may happen after the Google search app is updated automatically. So if this happens to you, try to just reinstall the app.
Forum discussion at Google Web Search Help.