Chemical? Progesterone?

LK
Long story short, I MC at 13 weeks with our first last January. We began trying again recently and I learned I was pregnant again with a very faint line on 8/9 DPO. I kept testing and the line was getting darker. Missed my period and went to get bloodwork. Came back progesterone 4.65 and HCG 20. So not where it should be for about 3-4 weeks pregnant. My doc just started me on progesterone, which is already making me feel awful. My temp is dropping and I go for more blood work today. My question is: if this baby is not viable, is the progesterone prolonging a MC? I would rather it not, so we can start over again. I feel like I'm in limbo. I also do not feel pregnant at all. My guess is this was a chemical pregnancy. What do you think? What has been your experience with chemical pregnancies and progesterone? Thank you!