Anyone ever have allergic reaction to ultrasound gel?

I am 35 weeks and do have very sensitive skin. But this time I had an NST done and I’m assuming I’m havin an allergic reaction to the ultrasound gel they used. I have a perfect circle where the monitor was and now it’s welting! I’ve never reacted to it before. However, I had a terrible reaction to my previous c-section and my whole stomach broke out in a rash and welted. Super painful and itchy. I’m scheduled for another c section at 39 weeks unless I go into labor sooner. I’m so nervous bc I can’t deal with more allergies and it’s just SO itchy. Anyone ever have this?? Any ideas how to stop it??? Itchy and nervous mama here!