hello, i took postinor 2 my menses came for 2 days and stopped then came 3 days later accompanied by nausea, vomiting, stomachache that comes out as gas then headache.doctor gave me secnidazole, vitamin b complex, paracetamol and danciflox and even though am still taking the last three since i have already taken the first i still feel nausea and vomit. What could be the problem?