This paper focuses on the relationships among education, self-tracking technologies, and body practices, addressing an ongoing debate about the 'disciplinary versus empowering' role of health tracking technologies in teaching people how to live. Using a Feminist Science and Technology Studies approach (FSTS), it inquires into the understandings promoters of such technologies have about the body as a 'pedagogical site' in the specific context of fertility tracking apps. Drawing upon empirical data from a multi-sited ethnography of technology fairs and experts' congresses, this study offers an analytical tool (the Body Tracking Configurations Matrix) to unpack and situate the multiple ontologies of the body in fertility tracking apps.