I had my ultrasound this morning. The good news: the baby had a heartbeat of 162. The bad news: the clot was larger. The MFM doctor said she would have expected this -- since I'd rushed right back to the hospital when I was bleeding, I probably wasn't done bleeding, so it was not surprising that the clot had grown. The hope is that it is done growing and will start to break up.
She felt that there were two pieces of positive news -- the heartbeat, which indicates that enough placenta is still attached well that the baby is getting what it needs, and the fact that I am not bleeding out my hoo-ha much at present. She thought that if the clot was still actively bleeding, the chances were that I would still be bleeding out bright red blood.
I asked about the baby aspirin, and here's the explanation she gave me. Baby aspirin is used in infertility treatments because there's a theory that aspirin prevents little clots from forming in the uterine lining. But when you have a big clot, you want it to go ahead and clot up so that the bleeding stops. She said there were other ways of looking at this, which is why some people end up being told to remain on it. But that answer satisfied me. She did say that the change that the aspirin causes in the platelets is permanent and that platelets live for 7-10 days, so the effects from stopping the baby aspirin wouldn't happen for a week or so.
Even if this resolves, she said I would still be at risk for PROM and placental abruption, as well as possibly IUGR, so I will need to get monthly ultrasounds. She also still called the clot "small," though it looked pretty big relative to the sac to me. But I hope by Thursday next week (when I go in again) it looks smaller.