The emergency contraceptive pill is effective in preventing pregnancy in almost 95% of the cases. However no amount of the emergency contraceptive pill is fool proof. It does carry along with it its own drawbacks and possibility of having a pregnancy is still there. The pill is effective only if it is taken within 72 hours of unprotected intercourse. If it is taken beyond this, then the effectiveness of the pill decreases drastically. If you have any long term medications like epilepsy or any antibiotics like rifampicin or any medication to prevent the spread of HIV infections, these pills reacts with the I pill and cause in the decreased interaction of the drug. So if you take these medications, it is better to consult the doctor and go ahead with the drug. Remember that the drug gives protection only for one act of intercourse that has happen within 72 hours from your taking the pill. Any other subsequent acts should be covered with another new I –pill. So taking one I –pill is not going to give protection for any intercourse within that one month. Pill is not any abortion inducing agent. So if you are pregnant beyond the point of intercourse, then the pill is not going to cause abortion in an already existing pregnancy. So if you miss your cycle even after taking the pill, it is advised to get a pregnancy checkup done to make sure that there is no pregnancy that is being carried on.