Ovulation predictor kits (or 'OPK's') take the guess-work out of determining when you ovulate.

Ovulation occurs when a mature egg is released from the fallopian tube. If sperm are present at this time, that egg may be fertilized, and conception occurs!

OPK's determine when you will most likely ovulate during your cycle.

How Ovulation Predictor Kits Work

A hormone, called luteinizing hormone (or LH), surges in a woman's body just before ovulation. This surge in LH pushes the egg out of it's follicle.

OPK's measure this surge in LH. Unlike charting your BBT, these kits PREDICT ovulation - not just confirm that ovulation has already taken place.

When a spike in luteinizing hormone is detected with the OPK, ovulation will most likely occur within 12 to 36 hours.

Tips On When To Use Ovulation Predictor Kits

- Test every day at the same time. If you measure one day in the morning, for example, and then the next day in the late afternoon, you may actually miss the LH surge;

- Test in the mid-afternoon, around 2pm or so. LH is usually produced in the morning, so you will be more likely to catch the LH surge in the afternoon;

- Start testing with ovulation predictor kits according to how long your average menstrual cycle is. Use the following chart to determine when you should start testing:

Take Advantage of Your Window of Opportunity to Conceive!

Keep in mind that once you detect the LH surge, ovulation will most likely occur within 12 to 36 hours.

This ovulation "window" is short (the unfertilized egg has a short 24-hour life-span), and only occurs once per month. It is therefore vital to take advantage of this time and have intercourse within this time frame.

Please bear in mind that sometimes LH will surge, but ovulation will not occur. Ovulation doesn't necessarily occur every cycle.

Tips To Maximize Chances of Conception With OPK's

- Start having sex a couple of days before your first day of testing with the ovulation predictor kits;

- Have sex every other day from that point on so that your partner's sperm have a couple of days to build back up the next time you have intercourse;

- Once the LH surge is detected, start having sex every day for 3 days straight.

By having intercourse before you ovulate, you will have sperm present in your body when the egg is released. This is the optimal condition for conception!