The BBT (basal body temperature) is the oldest method to monitor ovulation, and it requires a special thermometer designed to measure the basal temperature.  It has both advantages and disadvantages:  1.  You must remember to shake the thermometer down before you go to bed at night, because shaking it when you arise in the AM may give you a falsely elevated reading,  2.  It is both cumbersome and tiring to take you temperature even before you get out of bed to use the bathroom.  The advantages include: it’s inexpensive, and will give your physician evidence that you have ovulated in the past cycle.

The OvWatch is a fairly recent medical device.  It measure the chloride surge in the skin which precedes ovulation by 5 days.  The device which looks like a sport watch and must be worn continuously for 8 hours each day.  Not to have your girlfriends question you about your new watch you can put it on when you come home each night.  The most important point is that it you must put it on at the beginning of your menstrual cycle, and no later than cycle day three.