Dark spot on Urethra

Okay, so I just noticed this last night so I’m not sure if it’s been there a while or if it’s new, but I noticed a dark spot on my urethra on my left side. It seems to have gotten larger within the couple hours between checking it last night but hasn’t gotten bigger today. It doesn’t hurt but I’m not sure if it’s causing my cramps to worsen or giving me pressure down there/in my lower abdomen. I have tried to wipe it off thinking maybe it was discharge after I changed my tampon & it didn’t move. It’s not really swollen or protruding & it doesn’t hurt to the touch at all. I have read up on it & it doesn’t look like an std so I’m thinking skene’s gland blockage but If you ladies have any experience with this please help a girl out!