As another RMC sufferer I can completely empathise with how you're feeling. It is so, so difficult, your mind is in a constant whirl, and your emotions are all over the place. I know how you feel, and to get through the it myself I had to stop everything - no more POAS, tried very hard not to Google anything, and tried to just sit with the uncertainty. It's not easy. I don't think it means anything if the lines don't get darker, I don't know. But you'll drive yourself crazy trying to guess what's going to happen. There's nothing you can do about the outcome of the pregnancy, all you can do it look after yourself in the interests of looking after your baby. Do the things you can control - folic acid, vitamins, rest, fluids, etc.
I'm sorry you're going through this, it is such a hard thing to get through. I'm pregnant again after 5 miscarriages, I'm (hopefully) 14 weeks and I've found that the endless anxiety hasn't really gone away, but I feel better day to day now that I've learned how to deal with it a bit. Still have bad moments! But my psychologist told me that I'll be just as devastated to lose the baby whether I'm anxious every day, sad every day, or happy every day. You can't really protect yourself from how hard it will be if you do lose the baby, but you can find ways to stay strong and resilient and make each day less of a nightmare to struggle through. I always think of the kids I WILL have in the future and the kind of person I want to be for them, and it helps me.
Keep your chin up, OP xxx