Suggest Ways To Deal With Craving During Pregnancy

Im 28 weeks pregnant and i start about a month ago of craving soap. I love soap I can t control my self, so I just lick solid soap (Dove) sometimes. I already told my doctor about it, she told me to do the iron test, and like the doctor said I have low iron. She said she will call later to tell me what to do but till now after 3 weeks she didn t call. However now every single day I lick dove solid soap just a little bit to stop the craving but next day I wake up with the craving again... By the way, I only now take vitamin D and calcium too. What should I do? Will that hurt my unborn baby?