Ovulation is the release of an egg from the ovary. The egg then travels into the fallopian tube where it is ready to be fertilized. In order for conception to occur, the egg must be fertilized by sperm within approximately 24 hours of its release from the ovary. This is quite a short window of time and is known as the ‘fertile time’.
The LH surge
Immediately prior to ovulation, the body produces a large amount of luteinizing hormone (LH) which triggers the release of a ripened egg from the ovary. This LH surge usually takes place in the middle of the menstrual cycle. Ovulation prediction kits or OPKs as they are known for short detect the LH surge in urine, signalling that ovulation is likely to occur in the next 24-36 hours. Ovulation prediction tests help you predict the time of ovulation, and peak fertility. It is during this fertile time that conception is most likely to occur.