Blood in CM? Help x

Lydia • 19.. TTC for my first baby.
Hello everyone :) 
Just after some advice on CM.
My fertile window ended on Saturday and my AF is due a week Friday... I've just wiped and noticed that my CM had a pink streak in it. This is the second time I've noticed this.
Can anybody please give me any advice on what this might be?
(Also last night I had a dream I did a pregnancy test and it was positive) 
Thank you x