A fertility monitor is a digital device used for monitoring your fertility cycle. Some brands are sold only to assist in getting pregnant, while other brands are advertised for both pregnancy and birth control.

Fertility Monitors watch for a number of different fertility markers, including hormone levels in urine, basal body temperature, and the electrical resistance of saliva and vaginal fluids, or a combination of these methods.

The fertility monitor marketed by Clearblue Easy uses disposable urine test sticks. It identifies up to six fertile days per cycle and is recommended by the manufacturer as a pregnancy achievement aid only.

OvaCue measures the electrical resistance of saliva to determine approaching ovulation. It is sold with an optional vaginal sensor to confirm ovulation has passed. It is marketed for pregnancy achievement only. It is manufactured by Zetek.

OvuLens is a microscope to observe characteristics of saliva. Ovulation increases the level of minerals / estrogen in a woman’s saliva. Beginning three or four days before ovulation then returning to normal two to three days after ovulation. This change can be noted by observing ferning patterns in dried saliva.

Here are the current listings on eBay for Fertility Monitors: