Mention any two event that are inhibited by the intake of oral contraceptive pills to prevent pregnancy in human

Dear student,
The two events that are inhibited by the intake of oral contraceptive pills to prevent the pregnancy in human is
a)Implantation
The environment of the cervical mucus is changed to prevent the sperm entry and thus affecting the implantation.

b)Ovulation
It also prevents the release of the ovum or egg from the ovary.
Regards