Subtalar joint

I need to make another appointment with the foot and ankle doctor, but I am kind of wondering what they could even do while I'm pregnant? No x-rays.  Maybe a cortisone injection.  At any rate, my pain is not (or at least is no longer) in my talonavicular joint, it's now clearly (after lots of google image searches, haha) the subtalar joint.  It will be FINE enough for me to run (the tiny bit I still do) or walk, but then randomly if I sit, or sometimes when I sleep, the pain starts and it HURTS.  I just today went off the Voltaren (causes heart problems if taken in the third trimester, so at almost 21 weeks I want to be off of it) so am kind of worried it will get worse, but it's such a random pain. Not related to using it, more related to rest...almost like it just gets itself into a weird position and then if I force myself to walk around on it (can't do full weight bearing, but I hold onto furniture or the wall) it usually will work itself out in a few minutes.  So, different from all my other RA pain.  But that's the way it is.