The fact yours are pretty dark still tells me you haven't missed it. On the cycles before clomid, I would get the same thing. They would sit at almost pos for days and I'd be lol then day 18/19/20 I'd get the pos. But mine always get progressively fainter after I ovulate. So I did one late last night and the line was darkish but not pos. This morning it was only light to med. If you had ovulated they would be getting fainter and they aren't.