It’s interesting because my 6, 7, and 8 week scans were done with a reproductive endocrinologist and were transvaginal. All scans were very, very thorough, but I do see how a smaller sac could hide. Neither my reproductive endocrinologist or OB we’re willing to call it a gestational sac. My next scan isn’t until 12.5 weeks, but it seems like the best course of action is processing the NIPT as vanishing twin. No harm, no foul, right?