I take progesterone shots twice a week for the whole 1st trimester. My levels started at 28- then dropped to 26- and now 19. I lost my last pregnancy at 16 weeks after a big drop. I had another u/a today to check baby and everything was good. Any questions, just let me know. I've had alot of issues with progesterone.
My progesterone was very low with my first pregnancy (around 7) and I miscarried at 8 weeks. This pregnancy it started at 18 and then fell to 13, so my doctor put me on supplements. However my hcg levels have been rising but not doubling, and the sac around the baby is very small. So, the outcome is unlikely to be good, unfortunately. :-(
Anyway, I'm now at 9 weeks and had very slight spotting which the progesterone seems to stop. I'll find out next week if this pregnancy has a chance.
In your case, what is your hcg level and is it doubling? My understanding is that usually is more indicative of pregnancy outcome than progesterone numbers. Also, there are many studies that show that pregnancy supplements don't have any effect on a normal pregnancy. It's possible that it works for pregnancies where low progesterone is actually the problem, however. Unfortunately, if there's a major problem with the embryo, you'll probably miscarry regardless of supplements.
Try not to worry yourself too much and let us know what the doctor says. Good luck!!