Hi, You took plan B pill 30 hours after unprotected sex. It will effective upto 72 hours after sex. It will not prevent against pregnancy if pill was taken after 72 hours of sex. In present scenario, Plan B pill 80-85% effective in preventing pregnancy. But it cause hormonal imbalance, delayed period by 1-2 week, earlier period and excessive bleeding can occur. So do not worry if period will delay by more than 1 to 2 week. Meanwhile avoid stress, take healthy diet, drink plenty of water, do regular exercise. If period will be delayed by more than 2 weeks then consult gynecologist. Hope this may help you. Contact further if follow up needed. Best regards, Dr. Sagar