It sounds to me like pica, sweetie. It tends to be relatively common in pregnant women - Lauryn Hill suffered it during her pregnancy (she craved fingernails, corn starch and soil, according to a magazine article I once read lol). As the others have said, it's believed to be your body's demand that a mineral deficiency be satisfied, so maybe pay a visit to your GP and have a chat to see if they can work out what your body wants and find a safer, tastier way to satisfy it Good luck!!