This professional highly accurate digital thermometer reads to 2 decimal places and includes a free fertility plan chart with every order. How does a basal digital thermometer help Basically there is a slight temperature drop just before ovulation occurs and then a distinct temperature rise of about 0.40 to 1.0 degrees Fahrenheit after ovulation takes place. By plotting your temperature change during your cycle, you will know when you have ovulated. Ovulation Test When a woman is about to ovulate, her body releases a large amount of a hormone called LH (Luteinising Hormone). LH is always present in your urine but the levels increase (surge) in the middle of your cycle, causing you to release an egg from the ovary. This process is called ovulation. If the LH surge is present, ovulation is likely to occur in the next 12 to 36 hours. Our ovulation tests detect the LH surge by measuring the level of LH in urine. Directions: 1. Do not use first morning urine samples as LH is synthesized in your body early in the morning. It will not show up in your urine until later in the day. 2.The best time to collect your urine is between 10am - 8pm. Pick a regular time that suits you best. How does a home pregnancy test work A home pregnancy test measures the presence of the hormone (HCG) in your urine. HCG is produced shortly after the embryo attaches to the uterine lining. The hormone then builds up rapidly in your body in the first few days following implantation. This pregnancy test is capable of detecting pregnancy as early as 6 days before your first day of a missed period. The further in to the pregnancy you are the higher the levels of HCG get and the darker the test line will get. How accurate are these tests All our tests have proven more than 99% accurate in laboratory and consumer studies.