I think my PS switched my implants and put the bigger one on the wrong side! Any suggestions?

In the operative record there will be a description of which implant was placed on which side. Your surgeon will show this to you to assuage your doubts.

Unfortuantely, the only accurate way to say which implant is which would be another surgery.  One thing to keep in mind is that the left may still look larger because it was larger to begin with and while different implant sizes will help narrow the difference, it will not make it go completely away.  I recommend patience and re-evaluating the results once you are fully healed.  Good luck!