Help itchy rash that won't go away

Kandi • Mom to 3 beautiful girls. Expecting august 2020

It started on my stomach but now has spread to my legs and arms. It started right after I found out I was pregnant. It itches so bad. Dr prescribed steroid cream oatmeal baths and benadryl it's not helping. Btw I'm almost 12wks now so its been going on for 6+weeks. Have any of you had this if so ideas how to treat it. Please help excuse my hairy legs and stretch marks