For a regular 28-30 day cycle, days 11-18 are considered to be fertile as this is the period when the ovum is released. As the sperms have a life of about 2-3 days and the ovum lives only for one day it is essential for intercourse to take place around that period for conception to occur. Also, movement or washing after intercourse is not advised. There is no food restriction. It is better for a woman with a retroverted uterus
to lie on her stomach after intercourse as conception in a retroverted uterus is slightly lower. Good luck.