Most women will not have any side effects with emergency contraception. Sometimes, emergency contraception can cause spotting or irregular bleeding about one week before or after your regularly scheduled period. Other possible side effects are nausea, vomiting, headache, dizziness, breast soreness, or cramping for 1 to 2 days after taking emergency contraception. If you throw up within 2 hours of taking emergency contraception, then you may have lost the pill and you should consider taking another dose. Please contact us if you throw up your emergency contraception within 2 hours of taking it.