Explanation

Oral contraceptives contains two hormones, progesterone and oestrogen. Oral contraceptive pills works in four ways (i) Inhibition of ovulation (ii) Inhibition of motility and the secretory activities of the oviducts (Fallopian tubes). (iii) Changes in the cervical mucous, imparing its ability to allow passage and transport of the sperms. (iv) Alteration in the uterine endometrium to make it unsuitable for implantation