You definitely should not compare pregnancies. No baby and no pregnancy will be the same as another, even when it's the same mother. In time you'll be able to feel movement.
Every pregnancy is completely different. Don't compare this one to your last one because you will drive yourself mad crazy! Your baby is on track 16 weeks is normal. The best thing is that you are feeling movement.
Im jst worried cuz w my first one I felt her sooner..nd w this one its so diffrent. It scares me somtimes.
If you're not at 16 weeks it's not uncommon. I did at 14 weeks with my first, she was positioned just right, but not until 18 weeks with my second. I am 16 weeks and just now feel small movements with this one. Some women don't feel movement until as late as 22 weeks.
Clysta is right. If you're a first time mom you might not notice the difference between gas and baby movements. More than likely it is your baby.
You might or you might not. A first time mother can expect to feel movement anytime from 15-24 weeks. Placental position can also influence when you feel it, as well as baby position.