If a man’s sperm contacts one of a woman’s eggs, she may become pregnant (ova).
This is what contraception seeks to prevent by doing:
keeping the sperm and egg apart
reducing egg production reducing the combined sperm and egg’s (fertilised egg’s) ability to adhere to the womb’s lining
For most people in the UK, contraception is free. Additionally, pharmacies and supermarkets sell condoms.
There are 15 different approaches, so you can pick the one that works best for you.
Barrier techniques, like condoms, are a type of contraception that aid in preventing both pregnancy and sexually transmitted diseases (STIs).
No matter what alternative method of birth control you use, you should still use condoms to safeguard your partner’s and your own sexual health.
What Are Contraceptives
A Doctors Guide To Medicine 