TVS 7weeks pregnant

Question mommies.. Ngpa TVS ako today and sbe sa result 7weeks and 3days pregnant ako.. 164bpm heartbeat pero walang nakitang yolk sac.. may fetus nman at gestational sac.. ano ba ibg sbhin ng no yolk sac? should I worry? bukas pa kasi visit ko sa OB.. worried lang ako sa no yolk sac.. Anyone who had the same exp?