My baby is so low!!!

So my uterus is up to my belly button according to the doctor which is where it should be at 20 weeks. But most of the time I feel my baby like down in my pubic bone area. And on the ultrasound her head was like just chilling down there. AND I have a low lying placenta (which is slowly moving up I was told), and she's like, burying her face in it. 
Like you have all this room baby just move up a little!