Episode 123: Can Your Fertility Monitor Really Tell When You Ovulate? | Dr. Thomas Bouchard

How accurately can an at-home fertility monitor actually tell you when you're ovulating? In this episode of The NFP Podcast, Amy sits down with Dr. Thomas Bouchard, family physician, clinical assistant professor at the University of Calgary, and researcher in menstrual cycle monitoring, to unpack his newly published research validating the Mira fertility monitor against ultrasound-confirmed ovulation and serum hormone measurements. Dr. Bouchard takes us behind the scenes of the study, which followed regularly cycling women through intensive hormone testing, bloodwork, and follicular ultrasounds. The result is a fascinating look at what is actually happening inside the body when our fertility monitors show estrogen, LH, and progesterone changes. And one of the findings may challenge the way you think about the familiar “LH peak.” Amy and Dr. Bouchard discuss how ovulation can sometimes occur while LH is still rising, why an obvious LH peak isn't a perfectly precise marker for the moment of ovulation, and how quantitative hormone monitors can reveal changes that simpler “low, high, peak” systems may miss. They also explore the value of progesterone (PdG) for confirming that ovulation has occurred, the importance of first-morning urine and testing timing, and why hormone levels in urine don't necessarily correspond perfectly with a blood sample taken many hours later. For NFP users, the conversation raises an especially important question: Does having more hormone data make avoiding or achieving pregnancy easier? Dr. Bouchard explains why a fertility monitor should not be confused with an NFP method. The monitor provides biological information—but couples still need an evidence-based framework for identifying the fertile window and applying that information to their family-planning intentions. He discusses the Marquette Method, the importance of multiple fertility indicators, and why couples who are highly motivated to avoid pregnancy may benefit from more conservative rules and guidance from a trained instructor. Finally, Amy and Dr. Bouchard look toward the future of fertility technology—including the possibility of continuous hormone monitoring—and ask whether more data will necessarily translate into better decisions. Whether you use Mira, Clearblue, the Marquette Method, another fertility-awareness method, or simply want to better understand the incredible hormonal dynamics surrounding ovulation, this conversation offers a fascinating glimpse into what the latest research is teaching us about reading the language of the female body. The bottom line: Fertility monitors are giving women unprecedented access to their hormonal patterns—but understanding those numbers, and using them responsibly for family planning, requires more than simply waiting for a monitor to say “peak.” Resources: 1. Recent journal article: https://www.rbmojournal.com/article/S1472-6483(26)00422-0/fulltext 2. Learn the Marquette Method: https://www.vitaefertility.com/ 3. Marquette Method on The NFP Podcast: https://youtu.be/--jJB7m5Bfs?si=oDrqaNBavE5oN0Rn