Hi & Welcome. I appreciate your concern for the safety & efficacy of I pills when used frequently in one month following unprotected sexual activities. Emergency contraceptive pills like I pills are for emergency use only and are not appropriate for regular use. Since you had unprotected sex 4 times, & each time took I pills within the required time framework, then in terms of pregnancy, you are protected. What you have done is given your body a massive dose of hormones when you took it the first time, which should only be used as an essential emergency contraceptive, at most, once in a cycle. I pill will be effective but you will be having hormonal imbalance due to overdose of I pills. Since you have already overdosed with 4 times in this month, the 5th pill will further add to the over dosage & you will likely suffer from the hormonal imbalance in terms of missed periods, very heavy bleeding and/or irregular bleeding. This can also be harmful for you in the long term. Barrier methods like condoms, diaphragm or you may start taking regular birth control pills to prevent unwanted pregnancy. Hope I could answer your query. A feedback is appreciated.