When dealing with conception the window of opportunity is a small one, therefore it is important to determine when and if ovulation occurs to optimize the chances of conceiving. One method for documenting ovulation at home requires a woman to keep a daily chart of her basal body temperature (BBT). However, ovulation predictor kits are more convenient, simple to use,  provide better accuracy, and are utilized only during mid-cycle.

The kits may not work well for women with irregular cycles, when a woman is sick or under stress, or for those who take fertility drugs, but they are useful because of their convenience, accuracy and availability online and in drug stores.