Measuring 6 week gestational sac

Ok so according to LMP I am 7w2d but I had a mc 2 months ago, only had 1 period between which was 4-5 days late so I believe I'm more around 6 1/2 weeks. I went for a scan and have an empty gestational sac measuring 6 weeks. (Also got my bfp hpt later than I expected so think I ovulated late) Anyone experienced this & what was the outcome? I am prepared for the worst my ob said it's most likely nonviable. Have a follow up scan in two weeks they're gonna make decisions with me following that scan if nothing is still there. My best friend said the same happened to her & when she went back 2 weeks later there was a yolk sac & heartbeat! I'm not trying to get my hopes up...