Surveillance culture promotes self-improvement through quantified self-knowledge. Digital devices and mobile apps are developed for self-tracking practices, and individuals collect and analyse data about their bodies and habits for numerous purposes. One area of self-tracking involves fertility tracking, through which women track symptoms and signs relating to their menstrual cycle, also called intimate surveillance. Previous research has shown that self-tracking technologies and software often leak data and affect and (re)produce understandings and knowledges of (female) bodies. This chapter explores the following: What are the imaginaries and practices of intimate surveillance among women who use digital apps or wearables to self-monitor their fertility? Through eleven interviews with women who engage in fertility self-tracking, I found multilayered motives and understandings in relation to self-tracking practices, where potential risks are appreciated. Simultaneously, the possibility of fertility self-tracking is seen as a general positive that enables self-knowledge and a sense of empowerment and ownership.