Sir,
I intercourse with my girlfriend on 17th feb 2013 she eaten morning after pills within 24 hours and on 24 feb she got her normal periods of six days long and 2nd periods on 28 march 4 days late from normal but 6 days long and with normal bleeding but on 5th April she suffered with headache, vomiting, stress, fever and abdominal pain is there any chance of pregnancy even after getting 2 normal menses cycles if yes please help we what I have to do

It is highly unlikely she is pregnant. But from what your describing if she uses tampons then she may need to see a doctor right away. Those same symptoms you desrcibe also fit for something called Toxic Shock Syndrom. Please tell her to visit her doctor right away if the symptoms haven't passed. This is something that is life threatening.