Any mommies who had anterior placenta

Hannah
I am 16 weeks pregnant with my second but this time I have an anterior placenta by this time with my first pregnancy I could feel movement on the inside with this one I can sometimes but then other times I will go 3 or 4 day without feeling anything it's making me a little worried I use my heartbeat monitor like one a week so I know she is in there I just was wondering if this is normal and if so when did you start feeling movement all the time?