I am not as far along as you are but I am also terrified that something has happened to baby. I have heard it's normal to worry about your baby's health. Many women do (including myself)
i can't wait to have an ultrasound done so that I can calm down a bit but also I am scared and stressing out from now until whenever it is that I will have that done.
I feel little flutters in my stomach sometimes when I am laying down for a bit. Relax and lay down a bit and pay attention to what is going on inside of you with the baby, you might be able to feel something.
I have read other posts where women have suggested drinking a cold glass of water or juice and then laying down for a while and feeling the baby move.
I hope this helps a bit here.
I know how it feels to worry like this
i wish you the best!!!