Opinions please!

At what point do you call your doctor when you notice a decrease in fetal movement? I'm 27 weeks, and in the last 24 hours I've noticed he has slowed down a lot. I can still feel occasional movements, but the normal things I do that always make him move aren't really working. My doctor told me last appointment that I shouldn't worry about counting kicks until 28 weeks, so I don't know if I should be worried or not 😭