Medo - bolha indolora de cor única no pênis

Diagnose please. Singular skin coloured blister on shaft, not painful, four days after unprotected oral, no pus no pain. Shares pigmentation with the rest of the shaft and not at all irritated.

image

More images here if need be: https://imgur.com/a/aPd0YcS Can't get to a clinic till Monday morning so I'm panicking

Please help anyone, my anxiety is through the roof