Need some help

bree

So I'm 11dpo and af ain't due for 3 days my period is pretty regular well all day I been wetter than usual tmi but I get up from bed and walk down the stairs then I feel a lot of wetness well it turn out to be bright pink (kinda watery)blood so I hurried to bathroom and clean up and put a pad on thinking it my period now its just a spot on my pad can someone please tell me wats going on? Ty in advance