Strong kicks vs weak kicks

Im feeling movements right now at 27 weeks 3 days but they are weak kicks. At around 23 weeks kicks were very strong like a hard thud and right now they are weak thuds but the number of movements is almost the same. Weak thuds/kicks have been since past 1 or 2 weeks. Is this normal??

I do have anterior placenta so started feeling movements from 21 weeks. Had a ultrasound scan at 24 weeks and things were fine.

Is this normal or should i be worried?