Does anyone know what the very, very faint, colourless line on a HTP test means? Does it mean anything? Or is it just a product defect? For example, if you are testing with a 10miu HPT and you get a shadow line does it mean you could have the HCG level hormone present but only somewhere between 8 -10 or thereabouts? I am basically asking because I got one today for the very first time using the same tests I use all the time. I am on CD30 of a 33 day cycle and I am clutching at straws!