Hi girls. I'm getting worried — I felt my baby's first movements at 18…

Hi girls. I'm getting worried — I felt my baby's first movements at 18–19 weeks. Now I'm 20 weeks but it's quiet; why is that and is this considered normal? I had a private ultrasound on August 10. At the ultrasound the baby moved a couple of times too, but I didn't feel it, we only saw it on the screen.