23 weeks, kick counting is making me anxious!! 😰

I started to feel my baby girl’s kicks when I was 18 weeks pregnant. I’m 23 weeks today and using the app Kicks Count. My baby girl was really energetic in the beginning and I used to feel distinct kicks and now, she has quiet days and when it happens, I freak out, go to the ER, see her on the ultrasound and the doctors always say the same: she’s totally fine, nothing to worry about. When she moves less, it generally lasts 1 or 2 days and the movements increase after that. I’m freaking out now because this is the fifth consecutive day that she’s less active and movements are only decreasing! Yesterday I went to the ER and saw her on the ultrasound, everything was just fine, doctors said I shouldn’t worry, that I was feeling her less because she changed her position inside of me, but looking at this chart, it’s impossible not to worry!! What do you guys think? Should I start to kick count only after 28 weeks like everyone says? Is this app (Kicks Count) making me paranoid unnecessarily?? Someone help me, please! Thank you!