So I had a miscarriage is April. I was measuring 8 days earlier than I thought I was. Pregnant again now. I thought I was 7&2. Measuring 6&1...8 days early again. We saw the heartbeat in both babies. The first the sac was REALLY small and we couldn't see the yolk sac. Idk if it was Bc it was so small or Bc it wasn't growing rights. So I'm trying to be positive. This time the sac is MUCH bigger AND the yolk sac is very much so present   Abt the same size as the baby. Has n e one had this happen where u measured a week or so early and all is well. My dr says is pretty common.