Vvvvvvfl?

My cycle length is always either 25 or 26 days. It's cd 27 so I'm one or two days late. It seems so unlikely though as hubs was away with work most of last month and we only BD twice! Once before and once after what glow showed as my fertile window. Is this possible? I am used to complete negatives but I think I just about see a vvvvvfl! This is a cheap Tesco (UK) test. Have given up wasting money on the more expensive ones!! Does anyone else see it?