I stopped taking progesterone at 13 weeks and was also scared. However, nothing happened...no spotting or cramping. Now I'm 17 weeks and everything seems to be fine. My doctor assured me that the placenta will take over at 10 weeks and if it doesn't you'll have bigger problems anyway. I'm sure you're fine.
I also stopped cold turkey at around 13 or 14 weeks...I can't remember exactly. As Sally and Ecologic said, there is no risk as the placenta has taken over now. So unless there is some reason that your Dr. wishes you to continue, it's fine. Do talk to him/her for reassurance.
Hi,
there is no risk to stop them at 19 weeks. Actually the placenta takes over at about 8 - 10 weeks. I stopped my progesterone (shots and vaginal) at 8 weeks, but continued on oral until 10 weeks.
You are surely fine to stop now. Yes, talk to your obe to also get her reassurance.
I got off cold turkey for my last pregnancy at 12 weeks: I had no problems! I was taking 200mg/day.
Discuss your fears with your obgyn, he/she will be able to reassure you. It's very unlikely you would loose the baby!