itching like crazy!

I don't know what is wrong with me. I am almost 14 weeks pregnant and I have been itching like crazy all over my body since my 9 week mark. I have tried everything from cortisone cream to colloid oatmeal lotion. Nothing is helping. The only thing that gives me any kind of temporary relief is gold bond powder but I can really coat myself in powder everyday. Please someone help me! Be covered in itchy rashes every day is getting so irritating!!!!