Ovulation is the release of an egg from your ovary. A hormone known as Luteinizing Hormone (LH) is always present in your urine. At about the middle of your monthly cycle, the LH increases suddenly to a high surge level which causes the release of an egg from your ovary (ovulation) about 12 to 24 hours later. To become pregnant, the egg must be fertilized with a sperm in time. Therefore, your most fertile time is when you are ovulating. Testing for ovulation can help you predict your ovulation time quickly and easily.
Women with regular cycles ovulate about two weeks before the arrival of their period. It’s harder to predict ovulation in women with irregular cycles, but it usually occurs 12 to 16 days before the start of her next period.
There are several methods women can use to help determine their most fertile days each month.
One method to predict ovulation is to track cervical mucus, which involves a woman regularly checking both the amount and appearance of mucus in her vagina. Just before ovulation when a woman is most fertile, the amount of mucus increases and it also becomes thinner, clearer and more slippery (like egg whites). When cervical mucus becomes more slippery, it can help sperm make its way to the egg.
Another method is the use of Home ovulation-prediction kits which take some of the guesswork out of figuring out when a woman is ovulating. The kits test urine for luteinizing hormone, LH, the hormone whose levels increase each month during ovulation and cause the ovaries to release an egg. The three days right after a positive test result are the best time for couples to have sex to increase their odds of becoming pregnant.