Reviews on Tesco Pregnancy Tests?

I know in other countries you don't have Tescos but its a big supermarket chain in Uk. I picked up on of their tests, although its blue dye. I didnt hold my wee, just got home and took it and this instantly showed up as the ink and wee went over the test line? Im confused? Is it a bfp or just a notorious blue dye trick? A few days ago I was testing and getting faint positives on internet cheapies and a Superdrug test, then started getting BFN's? with Frer and internet cheapies? So didnt bother testing anymore. Af is due tomorrow...