Could this have been a crab?

today I was walking into the bathroom and I saw something red on the seat of the toilet and it was very tiny but it looked like a spider but it was bright red and it was a little bigger then a 20 gauge earring whole. what was it? No one in our family carries STDs both my self and my brother and virgins and bother my parents have only had 1 sexual partner (each other) could it just be a bug or could it have ben an STD crab?