Withdrawl of penis before ejaculation. Also This method is only moderately effective because the time of ejaculation is very pleasant, specially for males. Some sperms may pass into the vagina before ejaculation Natural method of contraceptive are the natural ways to prevent fertilisation. These methods are $(i)$ Periodic Abstinence Couple avoid coitus or intercourse from day $10$ to $17$ of the menstrual cycle when ovulation is expected to occur $(ii)$ Coitus interruption or withdrawl method Withdrawl of penis from the vagina just before ejaculation so as to avoid insemination $(iii)$ Lactational Amenorrhoea (Absence of menstruation) This method is based on the fact that ovulation and therefore the cycle don't occur during the period of intense following parturition. Therefore, as long as the mother breast feeds the child, chances of conception are almost nil