When it's very early, can't see yolk sac. Don't worry too much! I can't rmb when I could see yolk sac but at 4weeks + or 5 weeks can't see, and by week 8 can hear heartbeat
Same experience for me, doctor scans and see no sav or baby. Took blood test and ask to come back another time… Probably it is too early.
Go for next scan. doctor will explain and advise you on this . I have a experience.
Joanne Fong