Just read your messages and wanted to reach out to say how sorry I am for you going through this, especially with little one at home.
While not exactly the same, I lost my little one and it was discovered at a private scan.. My EPU seen me the same day. Prehaps a phonecall to them to explain your situation (childcare, signs you have already etc) they might be able to get you seen a little quicker than Wednesday? I'd definitely get someone to take your little one too, or come and sit with you both. I was medically managed but was in quite a bit of pain once my waters had gone, more back pain than anything, and I don't think I'd be able to hide the discomfort from my littlest (and I have a high pain threshold for labour etc) plus you might need to go into hospital if you run into complications so having childcare already in place would be a benefit. All I wanted at the start of mine, and right after, was my earthside babies so I spent a lot of time on facerime to them but honestly, they were better off not witnessing me in discomfort or on edge.
Its a very tough situation and how to handle it best is very personal, but best advice would be to reach out for as much support as you can (including from the EPU)
BIG HUGS x