Blister

Hi: I have been jelqing on and off, this time I have notice a blister on the extra skin I have since I’m cut it’s on the opposite side of my circumcision scar, I was just wondering whether it is possible to have one on that area which is not on the shaft nor the head?

Because I have suspected that I have a jock itch, itching and redness with a peeling of the skin on my scrotum. I hope it’s not herpes