Ms Marie O'Shea:

The 12-week period starts from the first day of the last menstrual period. That is how doctors and other medical professionals would date a pregnancy. It is difficult for people who have irregular menstrual cycles, who are using contraception that failed, who do not have the typical signs of pregnancy or do not recognise those signs and for those who have chaotic lifestyles, as compared with people who have regular menstrual cycles and who would be more au faitwith whether or not they are pregnant. The clock starts ticking before conception. It would be-----