Which statements are correct regarding natural method of contraception?

(i) In periodic abstinence of avoiding pregnancy, couples not avoid coitus from day 10 to 17 of the menstrual cycle.

(ii) Chances of fertilization are very less during day 10 to 17 of the menstrual cycle.

(iii) Day 20 to 27 of the menstrual cycle may called infertile period.

(vi) In withdrawal or coitus interruptus method of birth control, insemination is avoided.

(v) Ovulation and menstrual cycle do not occur during the period of intense lactation following parturition.

(vi) Lactational amenorrhea method of contraception effective only up to a maximum period of six months following parturition.

(vii) As long as the mother breast-feeds the child chances of conception are almost nil.