Black maggot type bug found on my pillow !!!

[gemg]

Hello, can someone please help me identify what I bug i found on my pillow...ewww !!
It was the size of a mouse dropping,black, moves like a maggo or caterpillart, but had lots of little legs like a milliped. Its not the first time i have found one in my bed, last time was about a month ago. I have a 4 month old baby and want to get rid of them.
Am now cleaning every corner of the house, taking the bedding to the laundrettes !!

Any advice would really really be appreciated !!

Thanks