Hi Leyla, re. the OPK's. Yes it is possible to miss the surge. Your surge generally peaks and goes within 24 hours, so because you are testing at 6pm, your surge may begin not long after, so by the time it comes back to testing again, it could have gone. It is suggested that you test twice daily - morning and night - to make sure you catch the surge.

Are you getting ANY line on the OPK at all???? Coz if it is feint then it shows some hormones present....hope that helps a little. What has FF said, and have you also be recording CM.....that should give you some idea...