My doctor left me a message on my phone saying "a-z you are e-k" I have no idea what this means and I'm pregnant.

I have no idea. Was it spoken, a through z you are e through k? AND 'you are pregnant' or did you already know you are pregnant?
It sounds like code for where you are in the pregnancy? I'd ask the administrative/secretaries. They usually know everything like this.

Haven't a clue what this means. Why don't you call the doctor and ask him/her?