No movement

Salam.. I'm 20 weeks 6 days pregnant. Baby langsung tak gerak dari pagi start jam 7 stengah pagi td. usually pagi baby byk gerak. Is it normal?I experience severe backache but I didn't go to the hospital sebab mostly my relative said its normal and saya buat kerja2 rumah macam biasa since morning smpai skrg baru rest..