That middle of the night bleeding is really puzzling and upsetting, I'm sure. I really wish there were good answers to these things instead of just "wait and see."
If you're feeling uncomfortable announcing on Mother's Day, I'd just push it back. Maybe just announce to the rest of your kiddos? That would be pretty special without it being "public." Also, having them join in the prayer force couldn't hurt, either.
I agree about the progesterone. It doesn't seem like everyone else's doctors do this, but mine checked my levels weekly and adjusted the meds accordingly. I also stayed on through to the start of week 14. It is hard to know what the right answers are because there aren't any definitive right answers.
You are on my mind and I am praying and hoping that everything is just perfect and you're just having one of those unexplained bleeding pregnancies!