I have taken an OPK every morning for an entire cycle and never got a positive...should I be testing twice a day or should I switch to a different time of day? I did it in the morning because the instructions said that was the best time and it's the longest break from urinating! Any suggestions?? I started testing again in the morning for this cycle last week and I'm on CD 12. Should I switch to the afternoon or do twice a day? Thanks!