I was on the progesterone pessaries for the whole 12wks and aside from the gross discharge there wasn't too many side effects for me.
I did have a horrible headache for most of the 12wks but I have no idea if this was progesterone or something else. I read the side effects and headaches was one of them....
But really aside from that I had no problems with it and Im still pregnant after 1 MC and 2 Chemicals so Im happy.