I wouldn't worry too much about it.. I'm overweight myself and 15 weeks and feeling baby sometimes.. It's light, but I know it's there... IMO I NEVER do kick counts, only because it just stresses you out when baby doesn't move enough .. Your alway's thinking something is wrong when it's not..... I just got about my day and by the time I go to bed if baby hasn't moved then I'll put a call in to the Dr... Most of the time it's just cuz baby was awake all the night before and took the day off to relax... ;)
Considered that im overweight, my ob told me to expect only light movements on 20 weeks. Sometimes its 2-3 times per day but like what ive said its not daily. Sometimes every other day. If im lucky 4 consecutive days i feel movements lol! (sorry for my english)
Not for all women, nor not all babies. This is why kick counts aren't done till 28 weeks. Baby is still tiny and depending on factors such as mothers frame, placental position and babies position it can hide/mask the movement. If you ever get concerned, never hesitate to call your doctor.
some babies arent as active at 20 weeks, but ya you should feel the baby at least once a day. when you get further along you will have to count the kicks.