18 weeks pregnant and a bad stomach rash answer plz?

hello im 18 weeks pregnant and i started developing a skin rash only on my stomach 2 days ago i discontinued use of my Palmer's cocoa er formula because i think that's what may have caused it but then again it still itches badly and now it stings,, it feels very bumpy like tiny small bumps all around my right side and some on the left of my stomach. i did some research on pupps and i don't think that's it and pupps usually occur in the 3rd trimester im only in the second i had prior pregnancies and have 2 children and this never ever happened to me at all should i see a doctor or just get some cream for the itchy feeling i DO NOT scratch at all even when it itches me i DO NOT use any other cream or lotions on my body, and my soap is the same soap i been using for years ZEST what should i do??