Understanding HCG Levels After a D&C: What to Expect

Question
I am 35, and have 2 children.  I had a miscarriage on 6-5-05.  I found out I was pregnant again 7-15-05. That pregnancy ended in a D&C on 8-23-05.  Yesterday, 9-21-05, I took a pregnancy test just to see the negative which meant to  me that I "normal" again.  I was in for a huge shock, because the test was positive.  When I called my doctor, all they told me was to wait another whole month, then test again.  If it was still positive to come in.  They said hormones can stay elevated for 6 weeks. My doctor never did any blood work on me after the D&C to check my HCg levels, and he didn't do an internal exam at my 2 week checkup after my D&C.  Is this true that the positive is from "leftover HCG" after my D&C?  Should I demand blood work? Or could I be pregnant again?
Thank you for helping.  

Answer
After a miscarriage, your pregnancy test will remainpositive for up to 10 weks. It would be silly to have more blood work at this time. There is no reason for you to recheck the HCG level. However, if you wish, you can repeat it in 6 weeks. By then, the value should be less than 5.