Has anyone ever had a false positive on a digital test? I took a Tesco own brand digital last night 'pregnant' then another one this morning 'not pregnant', then a clear blue non digital 'negative' and Tesco own brand 'negative'. So 3 negs after getting a pos. I thought false positives weren't possible but am 1 day late with my period now. I'm like clockwork usually. Baffled!!