If not implantation, then what? (tmi)

10 DPO yesterday - at lunch time and before bed time I checked my cervix, on both occasions there was about less than half a teaspoon of bright red blood. But it never went on to my underwear. I checked again this morning at 11 DPO (still nothing on underwear) and it was just brown CM. What can it be? Iv read that the amount is too much and that the colour is too bright for implantation but it's certainly not my full blown period either. Any input is appreciated :)