HCG Levels Dropping: Understanding Potential Miscarriage & Next Steps

Question
My doctor called me to say my HCG levels were dropping. They had dropped in almost 2 days from 25000 to 23000. We decided to wait a few days and see if I miscarry naturally. Doctor said if I was home she'd have me do a D&C Monday, which was yesterday. I wasn't ready for that so I am glad I am here for that reason. I have no miscarrying symptoms, no cramping, no blood. I don't know what to do. My pregnancy symptoms also seemed to have gone away. Has anyone went through this and then miscarried normally?  I have searched info on falling HCG but I can't get conclusive info. My doc said HCG levels should double every two days through whole preg but I read online that at 7 or 8 weeks HCG levels back off and the placenta takes over progesterone levels. According to LMP I should be about 8 weeks unless I ovulated late which is very possible. I also read that once levels are over 20000 that HCG isn't a good way to test for a viable pregnancy as the levels start to level off. Do they actually drop? Also two different labs did the results.

Answer
Usually, in a viable pregnancy, HCG values double every 48 hours. If the HCG value has halved in 48 hours, it usually indicates a non-viable pregnancy. If the value of HCG levels off or does not drop or rise too much, it can also indicate the possibility of an ectopic pregnancy (tubal pregnancy). If you should be 8 weeks according to your LMP, then a sonogram should show a pregnancy in your uterus and there should be a fetal heartbeat noted. It is true that after 9-10 weeks, the placenta takes over for the progesterone secreted by the ovaries, but that does not affect the level of HCG. HCG levels are an excellent way to assess a viable pregnancy. If you have not had bleeding or cramping, you may have a "missed abortion" and that can be diagnosed with a sonogram. I think a sonogram would be your best course at  this point.