Doctor : Why they so different in some place/hospital?

I have some question about doctor. why some of them have different taught about medicine & treatment for pregnancy women? I stay in the city at Pahang, and i got flu, cough almost 5-6 days. Then during monthly check up, doctor from governement clinic gave me medicine for cure my sickness. At the same time, my cousin which stay in Perak also get flu + cough and doctor at there does not gave any medicine instead of the doctor asked her to stay at hospital to make sure the flu + cough cure by their observation only. I also went to private clinic, the doctor also say that she will not gave medicine but suggest to me to drink a lot of mineral water and keep take healthy food. i am so confuse, why some doctor have different taught.