Is it safe to switch Invisalign too early for just one time?

Ideally, you should switch out of your Invisalign aligners as per the schedule given to you by your treating doctor. However, the only reason that I usually let my patients skip out early and move on to the next one is if they have lost their existing aligner.  I may have them then spend an extra few days in the new aligner to make sure everything is where it needs to be before moving on to the next set. It shouldn't be a normal occurrence to skip forward faster than the prescribed schedule. 

In order to decide if you should switch out your Invisalign trays early, I would contact your treating orthodontist and have them examine how well your trays fit.  In my experience, it's better to follow the protocol that has been set by your treating orthodontist, rather then trying to speed things along.  Good luck!

One time won't hurt anything. Go ahead and switch if you have a good reason. Just don't make a habit out of it.