I used to crave ice chips so bad closer to the end of my pregnancy,I used to almost hope to go into labour just so that I could have the ice chips from the ice machine.I would go to the store and buy slurpies and then get my boyfriend to suck all the flavour out of it then I would just eat the ice.It was the weirdest thing for me.
I looked at that website and it said it could have something to do with low iron levels and I was anemic so that could have been the expanation with me.
Hopefully your doctor can tell you more and get it all figured out for you.
Good Luck!