Lack of movement

ma

I’m 24 weeks and recently I’ve had lack of movement. I don’t really feel her kick or move all at except maybe once a day for a split second. I used to feel her move more weeks ago, now it’s settled down. I had an OB appt today and there was a heartbeat so she’s fine. But like no movement? I do have a anterior placenta. I told my OB about lack of movement and all he said was if I go 24 hours without movement to go to the hospital.