Is it normal for a baby to just have an off day and move as much as he normally does? Or should I be going to doctor ASAP?

I’m 28 weeks 2 days. I can get him to move a little with light or if I shake my belly for awhile. But I’m not getting the kicks I was getting ALL of the time. He would kick around for a solid half an hour or so and then nap for an hour or two and kick around for another half an hour and then sleep again. That isn’t what is happening now.

Advise please! I am a very worried mama!