Either ask them to only list female doctors, or go the the business's website and look at the doctors there. And if you get scheduled with a male GYN doctor again and aren't told until you get to it, tell them that they should have informed you that the doctor was a man. Ask that they cancel the appointment without charging a cancellation fee because of failure to communicate on their part. (Any GYN practice worth a shit knows to ask if a male doctor is okay, because of how common it is for women to be the victim of some form of sexual violence or abuse, and being presented with a male doctor when they weren't expecting it and are in just a gown would trigger flashbacks for many of them.)