I also have severe heartburn and reflux post Mirena! I am using progesterone cream as well, starting the two weeks before my period until I get my period. The cream has helped me to sleep better and has helped with my nausea. I also think the cream has helped with my IBS, which is GREAT! It's been almost a year since I've had regular-looking bowel movements (sorry tmi!) and finally feel somewhat human again.
However, the heartburn and reflux are still there.
I have an appointment with a GI doc at University of Washington next Thursday, and am prepared to undergo an endoscopy. What I am NOT prepared for is a lifetime of GERD medication (Prilosec, Nexium, etc.)
The strangest thing is the progression of my heartburn symptoms. It began with severe heartburn and nausea without noticible reflux, and over the past three weeks has become 24/7 reflux without heartburn. My voice is hoarse and my ears hurt, I think from the reflux.
Needless to say -- after researching GERD and reflux I'm pretty scared and hope this all goes away as my hormones get back to normal.
I'm sorry we're in the same boat, but at least I know I'm not going crazy!