I went to take another OPK and after I'd done it I realised that I'd pulled a pregnancy test out instead. A faint positive came up within a few seconds, but I really don't think it's possible. I stopped my pill on 5th August and had a five day bleed on 1st September, assuming it was a period as opposed to a withdrawal bleed. It was definitely too red and too heavy for implantation bleeding. I've been getting positive OPKs since Friday. I'm assuming the pregnancy test is a faulty one as I can't see how it could be possible that I could be pregnant? The OPK is the top photo and the pregnancy test is the bottom one.