Slow rising HCG levels...is there hope for a healthy pregnancy? Did anyone experience this?

Ashleigh
My levels started off going down then all of a sudden started to rise again but not doubling. They went from 697-635 down to 300's then back up to high 500's then 737 and now 825. 
This is my 2nd pregnancy and my midwife and dr's are so quick to say miscarriage but is there honestly any hope? I have an ultrasound tomorrow and I'm praying everything is ok. 
Has anyone else have slow rising HCG levels and end up having a healthy pregnancy/ baby?