I recently hit my thumb on an object that after a day, a small blood color spot showed up on my knuckle. I was concerned it was a wart, since I do have HPV, but it did not look like anything I have seen other than a birth mark. About ten days later, the mark appeared to be peeling, and it fell off with no effort on my side. What could this hae been? I thought blood blister, but it was no larger than the size of a pin head.

Thanks in advance.