Give information about pills and implants used as contraceptives.

(N/A) Oral administration of small doses of either progestogens or progestogen-estrogen combinations is taken as pills orally.
Pills must be taken daily for a period of $21$ days,starting preferably within the first five days of menstruation. This pattern is repeated as long as the female desires to prevent conception,following a gap of $7$ days (during which menstruation occurs).
They inhibit ovulation and implantation,as well as alter the quality of cervical mucus to prevent or retard the entry of sperm.
'Saheli' is a new oral contraceptive for females that contains a non-steroidal preparation. It is a once-a-week pill with very few side effects and high contraceptive value.
Implants: Progestogens alone or in combination with estrogen can also be used by females as injections or implants under the skin. Their mode of action is similar to that of pills,and their effective periods are much longer.
Administration of progestogens or progestogen-estrogen combinations or $IUDs$ within $72$ hours of coitus has been found to be very effective as emergency contraception to avoid possible pregnancy.