Dear member, Thanks for writing to healthcare magic. A pregnancy happens when a sperm fertilises a healthy ova. Women produce on an average one oven per menstrual period. fertyl increases the no of ova per cycle so that multiple ova are produced. thus chance of conceiving is more compared to other cycles, It can be started from day 5 for 5 days as recommended by your doctor. you have not mentioned whether your husband s sperm has been tested . If not then its important that this be done foremost as without good quality sperm pregnancy chances are poor. Please write back if you have queries. Dr Bhagyashree.