I think this varies from person to person. If you are thin to start he will probably be able to feel it sooner than if you have some meat on your bones. I was around 24 weeks when it could be felt from the outside, maybe sooner. I'm wasn't thin by any means.

My son did what your baby is doing. He'd be kicking and kicking and when someone put their hand on my belly he'd stop.

Congrats to you and your little one.

congrats on the baby!
i think as the baby gets bigger and older youll be able to tell more an more when he moves