Should I be showing?

I am 21 years old and currently in the U.S. Army. I am 16 weeks pregnant with my first child. Recently my platoon sergeant (some e-7 a'hole) told me if I was pregnant I would have been shown right now. When I go back home yea I see my belly sticking out there. Maybe he aint seen it. So now I am scared what if I need to be shown a little bit more. My last Dr. check up, they told me the baby heart beat is good and its growing. Things that should have moved (inside of me) during the pregnancy did! But listening to my platoon sergeant has me all scared now. Its to the point where he make another nco go with to my appointments. I been told it doesn't look like I m pregnant. I been told by other mothers give it a month. Shoould I be showing? And what should I do with this dumb platoon sergeant of mine?