I normally have a 28-29 day cycle, last month af came a week late, probably stress and antibiotics, anyway I've been doing opk and the lines were there but negative for oh surge, but now seem to be getting lighter to barely there, is it possible I've missed my window and ovulated soon as my period ended because if I hadn't of been late last cycle I would have ovulated round about now or is it normal for lines to get lighter and then get lh surge later?  

I should add I struggled to conceive last time, I have blocked tube on one side and had trouble ovulating but was hoping it sorted itself out after my baby as after all the treatments I conceived her naturally after acupuncture... unless clomid was still in my system two months after it ended lol