Why wont he move?

Im 18weeks 2 days. I havent even felt the slightest flutter. At our gender ultrasound he barely moved for the whole hour we were there.

Also I have a fetal doppler and check his heart beat and I noticed hes pretty much always in the same spot. So the last few days I checked every few hours for a couple seconds at a time. He doesnt move. Hes always right there, it takes half a second to find him cuz hes always in the same spot..

I want to feel him move but it seems like hes too lazy. He just sits there in the same spot all day. At all the ultrasounds he has his legs crossed and he just sits there sucking his fingers.. I really hope hes ok. I know hes alive cuz he has a heart beat, but hes either reallllllly lazy or maybe theres a reason he doesnt move?