It is so great to hear other people's stories of using OPK! I used them for the first time last month and tested for 10 days straight- no dark positive line. From cm I think i ovulated very late in my cycle- day 26 of 36 day cycle. I had been using OPK from day 17 to day 26 inclusive- the line did get darker from day 23 onwards.

I am so relieved to read your stories- I thought because OPK was negative that I just hadn't ovulated. I had become really worried about it, particularly waiting for ovulation this month. It is good to find out that perhaps I did ovulate but that OPK didn't pick it up!

This month it seems as though I have just ovulated- day 18 (friday) or 19 (saturday). I have started charting temp, which increased yesterday (saturday), and cm had become more EW over last few days. Did OPK day 18 and came up clearly negative. Didn't use OPK yesterday as accidentally left packet at work- have decided I'm not keen on them anyway!