RASH BLISTERING SPREADING DAY 12 pregnant

Hey so I’m 30 weeks pregnant. I have this rash it’s not in the bottom of my feet or hands or in my mouth so hand foot and mouth has been ruled out. Doctor thought it might have been scabies 😷 found out it’s not. They diagnosed me with heat rash barely even looked at it. Everyone is saying there’s no way it could be heat rash I’m on day 12 it’s spreading up my arms and thighs and neck and it’s blistering bleeding and it’s beyond itchy kinda burns has anyone had this it’s steadily getting worse and spreading more I’ve tried everything to get rid of this! I can’t handle it anymore. Someone help