The cervix produces fluid that changes throughout the cycle based on the type of hormonal stimulation. This is observed by noticing the sensation or looking and the visual characteristics.

Body temperature is taken upon waking. It is a measure of basal metabolism—the amount of energy used only to maintain life. BBT rises and falls in response to hormonal stimulation.

Urine can be tested for metabolites of hormones, including luteinizing hormone. LH is released from the brain when a follicle is prepared to release an egg. LH then prompts ovulation.