Hey thanks for your faith in the health care magic.I have gone through your question and i understood your problem. yes mifeprin causes headache and irregular periods. Adverse reactions associated with mifepristone use for termination of pregnancy are abdominal pain, uterine cramping, diarrhoea, dizziness, headache, fatigue, nausea/vomiting and a resultant temporary anorexia, anxiety, asthenia, back pain, chills or rigors, dyspepsia, fever, insomnia, leg pain, leukorrhoea, pelvic pain, sinusitis, syncope or fainting, vaginitis and viral infection, decrease in haemoglobin, uterine haemorrhage, skin rashes and hyperthermia in a few patients. Some adverse events were related to the use of misoprostol with mifepristone on day 3. All of these Mifeprin side effects are relatively common and will usually decrease after day 3and usually disappear after 2 weeks. thanks