Is it normal?

Myra

I’m 17 1/2 wks pregnant with my third baby. My first passed shortly after being born, my second was born preemie, and we are hoping our last one will be here on time. For the past few days I haven’t felt the flutters like I did last week. Is it normal to stop feeling my baby? Should I just not stress it? I have a Dr appt in two wks for anatomy ultrasound. Any thoughts? I thank y’all in advance!