If your device haven’t yet received version 1709, it might be because that the update isn’t yet compatible with your hardware configuration. In this case, it’s recommended to wait, Microsoft has said that the rollout of the Windows 10 Fall Creators Update will take several months.
Also, there could be other issues to why you’re not getting the update, such as a problem with Windows Update or something conflicting on your device.
It’s best to wait a little longer to prevent problem during and after the update. I personally, I’m still running the Creators Update (version 1703), and deferring the new version, because I want to make sure Microsoft release a few quality updates to address any bugs before I get it onto my computer that I rely on to work every day.
Here are some resources that might help: