How do Ovulation Prediction Kits (OPKs) work?
Ovulation Prediction Kits have become quite popular and can be quite useful to help you find your fertile time. OPKs work by measuring the presence of Luteinizing Hormone (LH) in your urine. A surge of LH which is sent to your ovary causes your ovary to produce enzymes which in turn causes the dominant follicle to rupture and release the egg into the Fallopian tube. This is ovulation and it is expected to occur within 24 hours of the surge of LH. An OPK is thus expected to be positive the day before you ovulate.
