How do individuals make sense of their biosensor data? Focusing on two different health biosensors – an ovulation monitor and the consumer gene test - we discuss how individuals interpret their biosensor data by engaging in exchanges on online forums. Here, participants share and discuss ovulation patterns and genetic susceptibilities by drawing on a range of materials. We argue that it is through these biosensing networks that genetic and ovulation data become meaningful, and it is through this process that the biosensing body is acquired. We show how discussion and speculation, artefacts and body sensations, anticipations and corporeal imaginaries are part of what constitute and hold together the biosensing body.