See below. Some mothers do not feel the child move until late into the pregnancy. Your OB doctor should be able to check fetal heart tones and movement. This can be done via ultrasound to get a really good idea of movement. Talk to your OB doctor to express your concerns.
20 weeks. Feeling the baby move, called "quickening" in doctor circles, can vary in different pregnancies and different moms. In first pregnancies, the average time is around 20 weeks -- sometimes earlier, sometimes later. In second and later pregnancies, moms "know" what to feel for, and quickening typical occurs around two weeks earlier, around 18 weeks.
16-20 weeks. First time moms at about 20 weeks, pros at 16 weeks give or take.
Fetal movement. If this is your first pregnancy, you may start feeling the baby move around 17-18 weeks. If a woman has already had a first baby they may start feeling feeling fetal movement as early as13 weeks.