OPKs!!

Husband and I bd on Friday cd6​​ but he left for work for two weeks so that was our only chance. I have irregular cycles so AF comes at differant times each month I had long cycles then shot then normal. New to OPKs  I've been taking them in the afternoon does a dark line that's not as dark as the control mean you could ovulate soon?? We only ever have a slim slim chance each mob as he works outta town on a rotating shift :( please comment :)