A sample collection and testing device for analyzing blood is provided that includes a controller, a fluid flow pathway, a pump configured to move fluid through the fluid pathway, and an optical fluid measurement element configured to measure a light intensity of the fluid in the fluid flow pathway. The controller is configured to: start the pump to move a blood sample in the fluid flow pathway, receive a signal from the optical fluid measurement element indicating a detection of a leading edge of the blood in the fluid flow pathway, stop the pump to stop the moving of the blood in the pathway, receive a plurality of light intensity measurements from the optical measurement element, each light intensity measurement measured at a corresponding point of time, and provide a mapping of the light intensity measurements into an indication of a coagulation of the blood sample over a time period.