I forgot to mention this is my second pregnancy so I felt my baby faster than I did with my first :)
I'll be 21 weeks and would always feel my baby move too now today I haven't really and was worried. I do have the fetal doppler but my baby is breech and harder for me to find his heartbeat I'm sure their ok but not big enough to always feel them.
I felt some movement at about 20 weeks, but not a whole lot. felt constant movement until like 30 weeks...but every pregnancy is different. I'm 36 weeks now and this baby won't stop moving now! Lol
You're so lucky to feel it! I'm two days away from 19 weeks and haven't felt anything. What I've read is that its very possible your baby is constantly moving but since he/she isn't big enough yet you won't feel it as consistently as when you are further along. So it is definitely normal!