Your baby should be fine think about they have so much skin and other things protecting that it takes alot to hurt your baby you will not lose the baby over your son falling on it if you were to get punched really hard its possible or bad car accidents or falling on your stomache just try and remind him whats in you and to be more careful
Baby should be fine im 25 weeks nd i have a 2 yr old nd he has pounced on my stomach, kicked me in the stomach, head butted me in the stomach, nd a couple of other things because he is very playful nd entergetic so it's not like he does it on purpose nd everytime my lil one is ok but if your really concerned i say go get checked out
I would call labor and delivery or go to the ER to make sure baby is ok. Have you felt any movement since?