Newbie Silly Question

Hannah • || Ambition on Fleek ||
So my boyfriend and I had sex only once this cycle and it was 2 days before my peak percentage of becoming pregnant. I was not feeling confident at all until about 5 or 6 dpo I wiped and had one single dot, the size of an eraser or smaller, of blood on toilet paper and it was red. Any ideas as to what it means? Thanks ♡