Hey Delicate Dove,
I have not been through an MC, so I can't give any advice on this, however I have stressed so much during this pregnancy that I can only imagine the additional stress stemming from the realisation of how very fragile a baby can be. I mean, we all know we could lose the bub, but to actually experience such a loss could only add to the anxiety normally felt by a pregnant woman.

I think you need to recognise the feelings of anxiety, and employ a couple of methods to help you get out of the doldrums. I see you are 25 weeks now, not long to go! Most birth stories are extremely positive, even the more difficult ones. Women have been doing this for time immemorable and you are no different to the billions of women that have given birth before you. Your body is built to have a baby, and medical science takes care of the rest.

Allow some positive thoughts now and again - realistically there is little we can actually control anyway, we must rely on our bodies to do the hard work. Let your body do what it is meant to do and allow yourself some time to stress, but also time to focus on the good things - the nursery, the baby, how you will feel when the baby is finally in your arms, names, christenings (if you are having one), and all the other wonderful things that you dream of. The rest you can deal with if and when it happens.

Good luck, and know that you are not alone with the anxiety - it is definitely not a "sign" that things wont work out, it is merely a sign of how much you want this baby.