Spot on penis shaft, is it a syphilis chancre?

Hi everyone, I had sex with a female sex worker in a legal brothel 18 days ago. it was oral and virginal sex with condom. today I have just noticed a spot on my penis shaft, it's easy to notice when my penis is erect, there is no firmness or anything bump or indentation to it, and I don't feel any pain or itchiness. however it being a round shape and no pain, I'm wondering if it's a syphilis chancre? (photos below) Thank you.

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could be normal, could be lichen planus which is not an std…it is very hard to say, to me it does not look like syphilis or any std…
do you have any update? any change in symptoms/diagnosis?