Stopped feeling the baby's movements

B e A m * • ⚽️ #1 Jul 17 🌷#2 Mar 20 🚗 #3 Feb 24
I'm 23 weeks and I've been feeling my baby move constantly since week 16. From 21 weeks, his kicks have gotten so strong and so frequent. I thought they would just get stronger and stronger and that I would feel his kicks more and more often. 
However, his movements have been decreasing this past week. And today, I haven't felt him move at all. I did find his galloping heartbeat with the Doppler so I'm pretty sure he's still fine. But I can't understand why suddenly I stop feeling his kicks. Does anyone know the possible cause or have the same experience?
I do have an anterior placenta but I don't think it's the reason why I don't feel his movements much lately since I have been feeling them constantly for the past 2 months!