Rash on inner butt cheeks after yearly exam

Maiah

I went to the GYN last Tuesday for my yearly exam and Wednesday I had a rash right on the inside of my butt cheeks closest to my vagina.

I thought I was just having an allergic reaction to something used during my exam and that it would go away.

3 days later and after Benadryl it’s still here! Itches the worst at night. Any idea what it could be?