I had my 1st dr appointment, I thought I was supposed to be 6 weeks and 5 days but the baby measured to be 5 weeks 6 days..

My dr. didnt seem concerned at all, said everything looked good & measurnents a week off is not a big deal.. but I know my ovulation date is correct, i was using opks tracking it. I know the 1st day of my last period is also correct. I just dont understand why the measurements aee off. Has this happened to anyone else before where you know for sure of dates?, it just dont add up correct to me..

Iv had one miscarriage before and my dates were also off from what i had expected but didnt think much of it at the time so i dont remember how much off they were.. im oraying this isnt a similar experience.. hope i never have to go through that again..