Wa'alaikumassalam! Ahhh sakit kebas macam tu common je during pregnancy, especially when the baby getting bigger and pressing on the nerves, a few of my mum friends went through the same thing around 5-6 months. Try adjusting your sleeping position (side-sleeping helps!), avoid sitting with legs crossed for too long, and gentle stretching boleh help jugak. But since this is pregnancy discomfort, better check with your doctor or midwife to make sure it's just nerve pressure and bukan ada something else, okay? They might suggest physio or prenatal exercises yang aman untuk you.