I was about 16 or 17 weeks I think with the first one. But it's really not uncommon to not feel it until 18/19/20 weeks or even later - particularly if you are a larger lady or have an anterior placenta (this is where the placenta is attached to the front wall of the uterus - it tends to reduce the amount of movement you can feel particularly early on when the baby is still quite small).

Don't worry you'll be complaining about getting kicked in the bladder in no time