my gynae also prescribed me Duphaston. Yes Duphaston is VERY expensive!!!! i took it thru out the 1st tri.
4 week preg is abit too early to experience preg symptoms. mine started at 6th week. from that moment onwards, i puke all the way till 5mth+. LOL!!!!
anw, congrats on your pregnancy! tc and rest well. dont forget to take the folid acid and duphaston daily =)