dream sorry to hear about your mc. I had one in mid-October as well. It sounds as if your body is resetting itself after mc, so may just be a wtf cycle. I would keep testing every few days. Understand how frustrtaing it must be.
mrs we have been having sleep/bed issues with DS since he turned 2. he was really ill for a few nights and we had just moved him into a big bed (we skipped toddler bed). Then he started coming into our room every night, anytime between 12 and 5. At first I was putting him back everytime he came out, but (especially as was just after my mc) I found that I couldn't sustain it. Some nights I was putting him to bed 8 times, or no sleep between 2 and 4 and then I had to be standing in front of a class the next day. I was wtrecked form lack of sleep so after a few weeks I made a decision to just let it happen.
He's going to bed in his own room (and getting better...now we just stand near the door once the light is out and he's gone within 5 minutes) but still tends to wake up when we go to bed. I either then take him back into his own bed and wait for him to fall asleep or let him fall asleep with us and then take him back. If he comes in after 12 I let him be - often I don't even hear him come in, just wake up at 3am and he's there!
I would never have imagined that we would be in effect co-sleeping, and thought everything could be solved easily by just putting him back but for us it didn't work like that. We;ve made the choice that this is just how things are. he wants to be with us and I'm picking my battles.
It's just so weird as he slept through from 4 months and has been really easy until he hit 2.
I know that doesn't really help but what I'm trying to say is that don't feel pressured that he HAS to sleep in his own bed. Sicne I've been open about our issues, so many of my friends have colleagues have been telling me stories about their own kids. It's commoner than you think (kids refusing to sleep in your own bed) and you shouldn't feel like a failure that DC won't sleep in their own bed all the time. Once I let go of the guilty feeling of "this makes me a bad parent" then I think I started getting a bit more sleep and not waking up when he came in.
OTOH I totally understand that you want DC1 out and in their own bed with DC2 on the way!