not taking plan b right after sex?

Hi,
Welcome to ehealthforum,
If she has taken the emergency contraception within 48 hours of unprotected intercourse, it should help in preventing pregnancy (provided they were not sexually active without protection after taking it). Since the emergency contraceptives contain high doses of hormones, these can disrupt the normal hormonal and period pattern causing period/bleeding abnormalities and appearance of new symptoms (that can at times mimic pregnancy symptoms). She should have withdrawal bleeding after few days of taking emergency contraception that usually occurs within 5-7 days of taking the emergency contraception (which may not occur if the ECP is taken close to period time). Wait and watch for her next periods which can be delayed. She should visit her doctor/gynecologist for further evaluation if periods are missed or abnormal, or if she suspects chances of pregnancy. If pregnancy gets ruled out and if they intend to remain sexually active, she should consider getting started on suitable regular birth control measures to be protected (after her periods). She should be regular with birth control use as instructed. They should avoid having unprotected sexual contact and avoid repeat use of emergency contraception.
Take care.