Hello, Pupperino. Thank you for writing today.
Emergency contraceptives can disrupt the menstrual cycle, so there is nothing to do but wait.
Emergency contraceptives are up to 95% effective when taken as prescribed within the first 24 hours and up to 90% effective when taken within 72 hours. It works by preventing ovulation and stopping a pregnancy from starting. It will not end a pregnancy already in place. Side effects can include stomach aches, headaches, nausea and a general feeling of being unwell. The more frequently they are taken, the more likely a woman is to have side effects and an irregular cycle. They should be taken only for emergencies, not used as a regular method of birth control.
Symptoms usually start 2-7 days after taking the medication and may or may not include bleeding or spotting. If a woman doesn’t get her next period within a week of it’s expected date, a pregnancy test is advised. Periods can often be delayed or longer/shorter as a result of taking ECP. They should get back to normal by the second cycle. However, this can vary and we cannot predict what each woman's experience will be with ECP.