Implantation bleeding

Georgia
Yesterday I was surprised to find some blood in my underwear-5/6 days earlier than AF was due. 
I don't feel 'on my period' and I have none of my other usual symptoms.
The blood is bright pink/red, really light and only recently noticeable when I wipe. 
It would have been 8/9 days after ovulation. 
Has anyone ever experienced this? Advice please :)