HCG 18000 at 5 weeks?

Hi ladies - My beta hcg test just came in and it was almost at 18,000 at 5w1d. I have been reading positive things about high hcg levels (could be multiples) or it could also be a molar pregnancy or indicative of Down syndrome.

Are these numbers normal? Had 2 miscarriages prior (and 2 living babies before that) so am really freaked out about this one. I don’t go in for a scan til the 18th.