my mirena fell out has anyone else experienced this?,this is the second time this has happened

I have three children I got the mirena put in after my second was born,i had sever back pain and and bleeding then one month after getting it placed it fell out and i got pregnant the third time and missed carried so i just went without anything for awhile and got pregnant again after having my third child i decided to give mirena another try, it was a few weeks after i gave birth that i was able to get it placed again.the first time i got it placed it hurt so bad but his time i didn't feel anything and my periods stopped,everything was going good,some miner cramps.well about two weeks ago i started having sever abdominal and back pain and headaches and this morning i get up use the bathroom and was going to lay back down til the kids got up,my husband went to the bathroom and come back and asked me to come to the bathroom with him he found something on the floor,well there it was just laying on the floor i didn't feel anything come out no bleeding no nothing.now i'm trying to find out if anyone else has had it come out o.O don't really know what to do now.