Young people take advantage of the contraceptives and other tablets to avoid pregnancy. In your case, you offered your fiancé unwanted 72 to clear the menstruation but still this cycle has not appeared. Any product appearing in the market is throughly tested by the laboratory for its effectiveness and finally it reaches to the end customers. Time of action varries from patient to patient and s such it may take a couple of days to get the positive result. So, you are advised to wait a week before you take any step in this regard.
In case, you fail to get any result, you need to approach a gynaecologist for the further remedial steps. Termination of pregnancy may be the last resort for your fiancé in case she is unmarried. The doctor may advise some other tests to ascertain the chances of pregnancy. In that case, the advice of the Doctor is to be followed.
There are other alternative ways of avoidance of pregnancy such as usage of condoms, pills to be taken regularly by the ladies apart from female - condom. Such contraceptions need to be used in future cases.