I am pregnant its 5 or 8 weeks and in the sonography they could only see a single small gestational sac. No fetal pole and yoke sac and the Mean GSD is 10mms at 5 weeks. So I wanted to know what exactly is the problem why can't they see a yoke? Are there possibilities of miscarriage.

Lets assume you are five weeks along, your baby is no bigger then an orange seed at this point so actually no fetal pole could be detected, and at 8 weeks probably no difference. There isn't that much to see. Five to eight weeks is quite general if you were not tracking your ovulation period.

Think how small an orange seed is, and then you will understand.

Of course you are concerned and worried, so I suggest sitting down with your doctor and asking questions and be proactive about your pregnancy, and at your next ultrasound be sure to ask the technician questions if you are in doubt.

Good luck with your pregnancy !