Barely feeling baby move at 21 weeks.

Hi ladies! I'm almost 21 weeks pregnant and I have barely felt my baby move and when I do feel something, I'm not even sure if it's my baby. It happens very rarely and usually, it just feels like very light movements. I feel like every other pregnant woman felt their babies at like 15 weeks and I'm worried something might be wrong. I haven't had my 20 week anatomy scan yet (that's in 2 days) but I have a Doppler that I use at home and I can find the heartbeat easily. Idk has anyone else experienced this? :(