HELP HELP HELP

I have NST twice a week and I seem to head to the er which is triage a lot here lately I'll be 36 weeks tomorrow and my baby passes these test with flying colors. But when I get home he wont move for a long time. Yes I've layed down and drank stuff etc etc. I put a siren noise to my belly and still nothing. I was in triage yesterday and have an NST tomorrow. Do babies sleep a lot now? I hate to keep going to the ER but it's aggravating not knowing what's going on inside. I have a fetal Doppler I listen to his heartbeat. But any help !!! what is normal movement at 36? Do they sleep a lot?