I need your help! baby measuring 9 days behind

I really dont know what to think of this, as i am 100% sure about ovulation and implantation dates and i tested positive since 12 dpo. Today was my 2nd scan, i should be at 7+2, but was dated back to 6+0 😵 gestational sac, yolk sac, embryo no heartbeat. BUT we were in exactly 1 week ago and there was only the gestational sac with maybe a shadow of a yolk sac. Doctor said, that though development is so delayed in time, it grew perfectly from last week to this week and looks optimal for a 6+0 baby. We have to wait again for 2 weeks 😫 now my question - what is more important: the accurate stage of development on estimated time (me being 7+2 and also showing a 7+2 baby) OR the correct development within a timeframe that is independant from gestational time (like baby growing perfectly within 7 days, but being behind in gestation). Am i misscarrying? (scan from today and 7 days ago)