Nervous to stop taking Progesterone..

I've been on progesterone pills once a day at night since I found out I was pregnant at 3.5w along, I'm now 12w4d along and I plan on finishing out the script I have now  then stop. Or at least that's what my doctor wants me to do, says I should be fine by week 14 but I'm SO nervous to stop because it's my first time taking progesterone and this has been our first healthy pregnancy and first one to go this far...Obviously working really well!  I know I shouldn't be reading into what horrible scary things that can happen but bc of previous miscarriages I can't help myself! I don't want to go into pre-term labor early in my second trimester, I plan to mention this to my doc at our next apt April 14th. Any success stories or input on this from already mommas to healthy babies would be GREAT.😩