Recently, a listener sent this question in to Ask The Egg Whisperer: "Hi Dr. Aimee! Thank you for all the work you're doing and for giving us the opportunity to ask questions. I listened to your last show on the ERA test. And I would like to know whether an ERA (Endometrial Receptivity Analysis) test can be done to figure out the best implantation window in the case of a natural FET (Frozen Embryo Transfer) cycle?" I always love answering these questions. Let's look at the basics of IVF before we talk about the ERA test. I like to think of it in three stages: 1. Egg and Sperm come together to make an embryo 2. Embryo transfer preparation 3. Embryo transfer The answer is: Yes, I do the ERA test in natural cycle transfers as well, because I want to get it right. I want to know exactly when a patient should do their trigger shot. I want to know exactly what time I should be doing that transfer, so that I never look back and say, "Oh, I wonder if the reason why this test is negative is because I didn't get the timing right." Send in your fertility question for a future Ask The Egg Whisperer episode Subscribe to my YouTube channel for more fertility tips! Join Egg Whisperer School Checkout the podcast Subscribe to the newsletter to get updates Dr. Aimee Eyvazzadeh is one of America’s most well known fertility doctors. Her success rate at baby-making is what gives future parents hope when all hope is lost. She pioneered the TUSHY Method and BALLS Method to decrease your time to pregnancy. Learn more about the TUSHY Method and find a wealth of fertility resources at www.draimee.org.