yeah my 2 year old daughter did a few weeks ago. Had minor cramping but baby is okay and I have to remind her sometimes not to jump and climb on mommys stomach because her little brother is in there and she will say sorry.

My big 100 pound dog jump on my stomach I got Braxton hicks afterwards but the babies are ok they have a lot of cushion in there

Baby should be just fine, there is a lot of protection between him/her and the outside world. if your concerned tho, feel free to call your ob, you're totally fine calling if you need some reassurance from a doctor. that's what they're there for. I mean, don't call them over every tiny thing, but this is a legitimate concern, even if baby is just fine, most women would need some reassurance.

my son belly flopped on me. he's 50 lbs. I was fine and 30ish weeks at the time

Baby has a lot of insulation, you'll be fine. My son constantly kicks me cause he doesn't know better.