Understanding Progesterone and HCG Testing in Early Pregnancy

Question
I am estimated to be five weeks pregnant. I have had recurrent pregnancy loss for seven years with miscarriages between 4-6 weeks since first day of last period. I told my doctor I had a positive home pregnancy test and she recommended I have two HCG tests done two days apart as they levels should double and verify the pregnancy is progressing. I asked if we could add in a progesterone test as I saw on the internet that low progesterone can also cause miscarriage and there may be shots or suppositories as treatment if that is the case and detected soon enough. My doctor said she did not believe this would be beneficial and declined to add progesterone to my lab test. Should I seek another opinion or is this a common belief in the medical community? I have read that many other women are getting HCG and progesterone tested simultaneously.
Thank you,

Nova

Answer
I agree with your doctor. Progesterone is a very unreliable test to assess the progression of the pregnancy. A low value does not mean that there are problems and a normal or high value does not mean that the pregnancy is  progressing well. A serial paired HCG test is much more reliable and useful. So just go with what your doctor is saying in this case.