The yolk sac
should be visible by the end of 6 weeks usually. Please be patient. You are still 5 weeks and 1 day pregnant. You may repeat the ultrasound
scan at 6 weeks to 6.5 weeks and look for the yolk sac. If your HCG
levels steadily increases, it confirms your pregnant state.
Even I do not think it is Molar pregnancy
. It is not possible to visualize the yolk sac prior to 6 weeks many a times.
Hope this helps you.
Be patient and wish you all the best.