Anyone with a rash???!

I am now 30 weeks today and have had a bumpy itchy rash on my upper arm for the past couple weeks and it's not getting any better. I have tried so many things to heal it.. Bynedryl, aloe, oils, neosporn, calamine lotion, peroxide, warm compress.. Nothing is helping and it'll start to burn! At times I feel itchy all over but nothing visible, only on my arm. Is this normal during pregnancy?? I know hormones go wild. Any advice is appreciated.