Pregnancy can occur at any point during the menstrual cycle, although the risk during the first three days of the menstrual cycle is negligible. The risk of pregnancy following one act of unprotected sexual intercourse increases around the time of ovulation, however it can be difficult to predict exactly when ovulation will occur, particularly with irregular menstrual cycles.

Emergency contraception (EC) provides women with a safe means of preventing pregnancy following unprotected sexual intercourse (UPSI) or possible contraceptive failure. The term EC covers both emergency hormonal contraception and the copper intrauterine device.

In English law, pregnancy begins at implantation, i.e. five to seven days after fertilisation. Any method of contraception used before this time is not considered abortion and any method
used after this time needs to be carried out under the terms of the Abortion Act 1967.

Everybody in the pharmacy team has a role to play in the provision of EC, particularly EHC options, which are available as P medicines. Pharmacy technicians may be involved in providing women and other members of the team with information about the service and also undertake certain tasks associated with providing the service. Only pharmacists are allowed to use patient group directions (PGDs) under current legislation.