Hello, I have skipped a tray #14 and now I am almost done with a tray #15, which I have been wearing for 2 weeks and should replace today. Yesterday I discovered that the tray #14 was skipped and now I am not sure what should I do - go to the tray #14 and then wear the tray #15 again or just proceed to a tray #16. I have noticed that the tray #15 was a little bit more painful, but it seems that it fits me ok.