Opks first time using question

Hey guys! Yesterday around 4 I did an opk with a faint line which was what I was expecting for CD10. This morning I did an opk and the line looks even more faint :S but it's only CD11. I have a 28 day cycle. Did I miss it already? I'll try testing again around 4, but feeling a bit let down :(. Me and DH don't get to BD as often as we would like, so we've been trying to use opks this month (first time using them). Any advice would be great. Been ttc for 6 months. Had one m/c in December.