You have to sleep your left side .
It took me a while too. Im 24 weeks =6 months and am starting to feel movements. But its only usually when i lay down to sleep in my side. Its like tiny little bumps. Try laying on your side and put a tiny bit of pressure on the side of your bump :)
I agree with above. I'm also trying to figure out how many weeks 6 months is? LOL I'm math dysfunctional these days. I felt my baby move for the first time at 20 weeks. Try drinking a bit of orange juice and lay down-- see if you feel anything. My baby often felt like flutters that I didn't know were baby until later. good luck
Feeling your baby moving isn't always accurate depending on your weight number of pregnancies and activities it can very. Maybe you baby is more active while you sleep? Try moving around more. If your plus sized it might be a month or two before you feel it. If this is your first pregnacy you might not be identifying the movements when they come. If you're really worried discuss this with your doctor.