OPK tests

Could be you have ov'd but missed the surge peak, maybe next time you get a faint line try another test in 12 hours and you might catch it.

another thought....

False positive ovulation predictor test results may occur because your body may attempt to ovulate and not actually do so. The kits detect the surge in lutenizing hormone (LH) that occurs before ovulation, but they do not indicate whether you have definately ovulated. Some women regularly experience small peaks in their LH that occur before the actual peak that corresponds to ovulation. False positive ovulation predictor kit results are very common in cycles in which you experience split peaks or false ovulation. A shift in your basal body temperature can support that ovulation has occured. However, only an ultra sound can absolutely confirm ovulation.

maybe its still coming!!

I thought I had missed ov as I had fade in lines and then forget to do the OPK test the next day (big work do and totally forgot to head to the loo at 6pm lol), the next day OPK was negative again.

I didnt have a temp rise so I kept testing and got a positive about 6 days later.

It is possible for your body to gear up to ovulate and not actually surge. I would keep testing for another week if you have enough tests and if you get a fade in line test again in 12 hours like little star said.. I tested at at 10am, 3pm and 6pm.. but I a POAS addict lol.