Measuring 6w2d

So I am currently "pregnant" with my 3rd baby. I went to the doctor a week after I had blood work done confirming I was around 4 weeks and they did an ultrasound where they couldn't even see a sac but my hcg was good.

I waited almost a week and went back yesterday and they did a transvaginal again and couldn't see anything at all, so they switched to abdominal and found a gestational sac and it was very low so the transvaginal couldn't pick it up, but it was empty. It measured 6w2d.

I know it can still be too early, but I can't help but worry. With my 1st I saw him at 6w6d and with my 2nd I saw him at 7 weeks because I waited 2 weeks before going to an OB since they wouldn't see me until 6 weeks anyway, so seeing an empty sac was a little devastating.

I called my sister's to update them and the oldest one said she didn't see anything in the sac until she was 10 weeks because the placenta was forming in front of everything so nothing could be seen.

My other sister, who has had 2 miscarriages before (one she knew about and the other was a blighted ovum) said I should be able to see a baby by now and that it probably wasn't good, so that didn't help my anxiety at all

They told me that when I go back next week to not look for the worst but to prepare myself for it which also didn't help. I feel like this pregnancy is going to end and I am devastated.

Has anyone had the same experience?(0