to provide background on data that say that a beta hCG of 8k at 5 weeks is a soft marker for Trisomy 21. It certainly could be a concern for molar as you pointed out...which is an abnormal pregnancy. But in reading the Internet to the end, (and grilling my nurses after I had super fast doubling betas), I've never seen anything that says Trisomy 21 soft markers can be ascertained as early as FIVE weeks by testing beta hCG. If that was the case I would have gone crazy myself because I had fast doubling betas (like 24 hours!) and was also worried (without just cause) about having an abnormal embie.
If your beta hCG of 8k at 5 weeks is a soft marker for Trisomy 21, then is she factoring that into assessing your current results? If there is accuracy in her statement then wouldn't the fact that you already had a supposed soft marker be taken into account?
I really don't think that your 8k at 5 weeks was a soft marker for DS. I think it was a sign of a very strong and healthy pregnancy!!