What Causes Movements In Body While On Mirena Coil?

i've had the mirena for about 6 months now and for those 6 months I've been experiencing movement in my body like i can feel the mirena moving, also i've had alot of dizziness and breast pain for the past few days , I've had a child before and this is to a T what happened when i was pregnant with him and i only found out in my fourth month that i was pregnant so i am a bit worried that it would be a pregnancy in the tubes.