I think fear of the unknown is prevalent in every pregnant woman whether they have previously miscarried or not. Know that you are not alone in your worries and remember the best thing you can do to take care of your baby is to take care of and love yourself!
My first 2 girls everything was fine. Just with the last pregnancy its made me and my partner panic again we no our boy is fine in there and im constantly having scans all way thru pregnancy so makes me feel abit better. I no he'll be fine ill be better when hes in my arms :-)
So sorry to hear I have that same fear each and every day I'm 24 weeks pregnant and every little thing freaks me out. I pray for me and my baby girl. Like the post before said put your trust in god
You will be fine the only advice I can give you is to just keep your faith in God n take things one day at a time. I pray for my baby boy everyday that I wake up :-)