Its not true that ultrasound cannot detect early pregnancy. Moreover, as you said, if it is 5 weeks now, and doubt any problem/condition, best option i can suggest is go to Hamad Hospital Women's emergency and see the doctor (U may have to exxagerate a bit @ the emergency counter to see the doctoe quickly). They will definitely do Ultrasound and do consultation within half an hour. I had similar experience @ 5th week.