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If the unprotected intercourse was within last 48-72 hours, she can take emergency contraceptive pill (ECP) to help with preventing pregnancy. ECP works in preventing pregnancy if taken within 48-72 hours of the unprotected intercourse. For further help and assistance, visit her doctor/gynecologist. If the unprotected intercourse earlier than last 72 hours, then you will have to wait and watch for her next periods (to see if she is pregnant or not). Look out for development of any other new symptoms. If you intend to remain sexually active, then she should consider getting started on suitable regular birth control measure (as recommended by her gynecologist) after she gets her periods. Avoid further unprotected sexual contact.
Take care.