They are easy to use, and help you to accurately prepare.
- The ClearBlue Easy Fertility Monitor determines your most fertile days by measuring both estrogen and LH. It "learns" your cycle based on period lengths, ovulation day, estrogen and LH levels. The machine is turned on at the same time everyday and it will prompt you if it is a day you should be testing. If you are prompted to test, the test works much like the other tests mentioned on this page where a tester is exposed to your urine. In this case the tester is then snapped into the monitor rather than manually read. The monitor reports low, high and peak fertility days. The results may be a little less accurate in the first few months as the monitor "learns" your personal cycle. The ClearBlue Easy Fertility Monitor consistently gets excellent reviews by users.
Although it is not recommended because it is not as accurate as the monitor, the ClearBlue Easy Fertility Monitor test sticks can be read manually. Holding the stick with the wick to the left and the thumb hold to the right, the line on the right will indicate your estrogen level and the one on your left your LH level. First the estrogen level will rise (see Menstrual Cycle page), then a few days before ovulation it will lower and LH will rise. So when you have your LH surge, the LH line will be dark and the estrogen line will be very light. LH then goes down and after ovulation, estrogen will rise a little as some estrogen is produced by the corpus luteum.
- The Ov Watch is worn like a watch and predicts your most fertile period by detecting on the surface of your skin, the chloride ion surge that occurs 6 days prior to ovulation. It will alert you to the 4 most fertile days before ovulation plus the day of ovulation.
- Baby Comp / Lady Comp / Pearly are produced by a German company and have only recently been made available in the U.S. The Baby Comp has the most features and is the most expensive, followed by the Baby Comp and then the Pearly. On any given day, these products will indicate fertility of the next six days. These products determine your fertile period by reading and interpretting your BBT.
"The Lady-Comp monitor is a micro-computer, with a database of over 700,000 cycles to which it compares each personal temperature reading. It determines that the temperature taken is accurate and reliable for the day. With consistent use, the monitor becomes personalized to your temperature readings and detects slight variances occuring with ovulation. This information in conjunction with information regarding menstrual cycles allows the monitor to indicate to you the days on which you are likely to be fertile(indicated by red light). The monitor can also determine with 99.3% reliability, days on which you are infertile (indicated by green light)".