If you have taken contraceptive pills which are used for emergency contraception (EC )within 72 hours of unprotected sex, relax.....mostly the pregnancy wont occur. In the next 15 days you will get a menses....but it could be heavy or irregular If at menses bleeding is heavy please consult a gynecologist Even after the first menses, after taking these tabs....your menses cycle may remain irregular for few months. so it would be advisable to refrain from taking such ECPills now and then If you indulge in sex frequently then uts better to use condoms along with regular contraceptivepills. condoms also protect against sexually transmitted infections....