Hcg level at 6weeks

Erin
Just had my results back the reading is 3429
Doctor said she would like them to be higher for a viable pregnancy.... Just had 3 miscarriages in a row.... Now I'm stressed and scared... Bloods done again today. Hopefully I get a good result on Monday. 
I know it's very much up to individual bodies etc... Was wondering if I'm freaking out for no reason?