The pain-free monitoring of blood-based biomarkers is essential for early detection of diseases like cancers, infections, and metabolic disorders such as diabetes. While research often focuses on venous blood analysis, menstruation blood is an overlooked but promising source. Evidence shows a strong correlation between biomarker levels in menstruation and venous blood for many clinical analytes. A wearable, microfluidic monitoring platform integrated into hygiene pads is presented for electronic-free, naked-eye detection of disease biomarkers in menstruation blood (MenstruAI). Semi-quantitative detection of C-reactive protein (CRP), cancer biomarkers carcinoembryonic antigen (CEA) and cancer antigen 125 (CA-125), and endometriosis biomarker CA-125 is demonstrated. The biomarker-induced color changes can be read by the naked eye or a smartphone app with a machine-learning algorithm for semi-quantitative analysis. MenstruAI can revolutionize women's health by offering a non-invasive, affordable, and accessible health monitoring method, democratizing healthcare, and enhancing service availability and equity.