Once a positive test has been made, then ovulation should take place within the next couple of days.  The best time for a woman to conceive is between 2 days before ovulation and 24 hours after.  This gives a 3 day window from the time of the positive test during which sexual intercourse has the best chance of producing the desired result.

The emotions also play a major part in conception.  Most gynecologists will say that regular intercourse in a relaxed atmosphere is the best way to conceive.  In fact many have noted that women who focus too much on their dates and times of ovulation suffer a mental blockage that results in a poor chance of conceiving.

New ovulation detection devices are appearing on the market recently.  One new device is a "Saliva Tester" which is basically a small microscope that can be used to detect structures in the saliva that appear at ovulation.  These crystalline structures are also found in the cervical fluid at the same time.  Other new devices include computer controlled analysers of various types.