Larger yolk sac at 5 week 5 day

Hi everyone. Went for my gynae visit (2nd visit) and had a vaginal scan. Baby has grown a little bit since exactly one week ago (currently measuring 5 week 5 day) but doctor is concerned about a larger yolk sac (which could mean baby not absorbing enough). Has anyone had this and went on to a smooth pregnancy? I had a mc last year end and has been ttc-ing since then. Really anxious. Does my ultrasound look normal? Going back for a follow up in one week time.