Mini pills (progestogen-only pills or POP) are a type of contraception containing the sex hormone progestogen. This hormone makes the slime in the cervix more sticky, so it is more difficult for the sperm cells to move up into the womb and fertilise the egg cell.
Mini pills also affect the lining of the womb, making it impossible for a fertilised egg to attach itself to the lining once it is fertilised. This means that mini pills do not always stop an egg from being fertilised, and that the fertilised egg is rejected just after new life has started. Human life starts at fertilisation, so we would not recommend the use of mini pills as contraception.