no movement

Jessika • ♥️ 30 year old mommy to 4 sweet babies 3 on earth and one in heaven (born sleeping at 31 weeks 6 days)
31 weeks and baby has not moved at all today. I started a kick count one hour ago and still haven't had any luck. 
Tried to get his heartbeat on Doppler and also nothing. 
I am high risk and go for scans two times a week but they also want me doing counts if I notice sudden decrease in movement. 
Any suggestions ? 
When is it time to call in for this? 
I don't want to panic and call for nothing. But I was hospitalized for 3 days about a week ago for his heart rate suddenly dipping. He has a short cord and only one artery 😓