What should I look for when purchasing an ovulation predictor kit? Is one better than the other? Are they easy to use? Mary Ann

These tests are easy to use and relatively inexpensive. There is no one kit that is perfect for everyone. If your periods are regular and ovulation predictably occurs within a period of three to four days, then a six-stick kit is fine. If your cycles are more irregular, you may choose a kit with nine test sticks.

The test measures a surge in the hormone LH. If you have polycystic ovary syndrome or are on the drug clomiphene, you may already have high levels of LH. This may turn the sticks positive even before you have a mature egg. I would suspect this if you test positive within four days of your last clomiphene tablet, if your LH surge is positive for three or four days in a row, or if the surge occurs on day 12 or earlier in the cycle. If in doubt, a tranvaginal ultrasound exam to confirm that a mature follicle is present may improve the odds of conceiving.