baby kicking very low? Normal?

Vee💃 • First pregnancy 😘 EDD: Nov. 1, 2015 😁👪❤️
21 weeks I feel like my baby is kicking my bladder/pelvic area sometimes or something. Sometimes it feels like gas but i know it's not. I know what her little kicks/punches feel like. But my feelings of her are also a little muffled because I have an anterior placenta. So I don't know exactly where she is :/ but is it normal for her to kick so low? And can anyone with an anterior placenta tell me when they begin to feel more?