Understanding Rising hCG Levels in Early Pregnancy & Miscarriage Concerns

Question
I am 27 years old, no children.  Had one miscarriage in July of this year.

Currently, my LMP was 9/9/04 so I should be about 9 weeks pregnant.  I had an ultrasound last week that showed I was closer to 5 weeks.  I have had my Hcg levels taken three times -  on 11/3 it was 6700 on 11/5 it was 7800 and on 11/8 it was 9585.  What does this mean, am I having another miscarriage?  If so, why are my levels still rising, are there other explanations?  I go in for another u/s tomorrow and wnat to know what my options are, the dr is hard to pin down to talk to.
Thank you.

Answer
If your last period started on September 9, you should have been 8 weeks pregnant last week (You should be 9 weeks pregnant now). If the sonogram last week showed only a 5 week gestational sac, then either your dates are incorrect, or you may be miscarrying. The levels of HCG are not rising very quickly (it should double every 48 hours). You did not mention if they saw a fetal heartbeat on the sonogram. It may merely be a very early gestation and you should wait two weeks and repeat both the HCG and the sonogram. Good Luck. If, on the next sonogram there has been no growth, then it is not a good sign.