still not feeling baby move too much at 28w??

Summer
I've brought this up to my Dr numerous times and they just brush it off or over talk me and say I need to concentrate on his movement. I sit at a desk for 8.5 all day with very little distraction, I'm pretty concentrated all day and would know if I felt movement. I do know I have an anterior Placenta but I would have hoped I'd feel him a lot more by now. Any others go through this?? I Didn't even feel him after drinking the glucose drink!