normally the baby will not be in constant position while in uterus, it will be moving because of amniotic fluid
so may be because of the pressure of the gestational sac
you are feeling that baby is kicking,
you better visit gynecologist once and get examined to rule out and bulge of membranes,
try to sleep in left lateral position,
and avoid prolonged standing or sitting in same position,
amniotic fluid will mobilize the baby, so you can go for ultrasound
to rule out any abnormalities in amniotic fluid.