Mention any two events that are inhibited by the intake of oral contraceptives pills to prevent pregnancy in humans

Oral pills are a type of hormonal contraception.They contain progesterone like hormone and prevent pregnancy in following ways:

1. They prevent ovulation, thus provide contraception.
2. They also thicken the cervical mucus, and make it difficult for sperms to enter the cervix,  which provides additional factor to prevent pregnancy.