I need answers

Nicole

So I’m 6w 4d had a scan at 5w5d they couldn’t see anything, said maybe I am not as far along as they first thought. So I went for another blood test my Hcg levels are rising but certainly not doubling. All the drs say is it’s rising that’s good but I hate not knowing if this isn’t going to be viable. Has anyone else had anything similar, either with the scan of HCG levels?