Weird question..

Summer • 2014👶🏼💙2019👶🏼💙 24 Currently PREGNANT with #3 🤞🏼💗👧🏻

I’m not sure if this will make any sense but I am 30 weeks pregnant and sometimes when my son kicks me it feels like shaking like he’s shaking in there or something like jitters it would be very quick but I’m a little concerned anyone know what I’m talking about and have experienced this and it be normal? Never had this with me first?