Dark spot

Hello. I guess it should be in “injuries and treatments”, but I can’t post there yet.

Immediately after the first session of newbie routine (5 min warmup, 5 min stretches, 10 min jelqing and 5 min warmup), I found a small dark spot in the glans. It kind of looks like a mole, but on closer examination it’s dark purple rather than black. My search in the forum didn’t give any results. Could it be some kind of small bruising? Anyway, I decided I would stop to see how it evolves. I have a picture showing only the spot and surrounding skin, but I’m not sure it counts as genitalia picture so I won’t post it (unless somebody tells me I can).

The data asked in the injuries and treatments forum:
29 years old, gym 4 times a week mostly resistance, normal weight for height, no drugs whatsoever (including smoking and alcohol), no medications or diseases, overall balanced diet.

Thanks!