That isn’t likely. Hormones don’t cause our internal sense of gender - that’s something that is innate (built into us).
EMDR is a psychotherapy to reprocess a painful memory while your brain is simultaneously bilaterally stimulated. It's a fancy way of saying that you return to a memory while something (minimally distracting) is working to make sure both the right and left hemispheres of your brain are engaged. Here's my experience with my first session.