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Please wait for a week for your period to start. If it does not start by then, you will have to do urine pregnancy test to rule out pregnancy. Period could have been delayed due to stress. Another rare possibility is that of pregnancy.
Though you mentioned the days you had sex as your infertile days, sometimes occasionally ovulation could be delayed making the days fertile. Still you had taken emergency pill (though it is highly effective in preventing pregnancy, protection offered is not absolute). So, there can be little chance of pregnancy which you need to rule out first.
If you want to rule out pregnancy earlier, you can do blood beta-hCG test, negative result of which will rule out pregnancy. Other option as I told is to wait for a week. If pregnancy test comes negative and still period does not start, you can induce period by taking tablet Medroxyprogesterone acetate 10 mg twice daily for five days. Period generally starts within a week of last dose of tablet. It will not induce period if you are pregnant.