I started testing opk since day 8 of cycle-and same time everyday around 4pm and only 3 days around cycle day 24-27 a slightly darker line (still negative though) showed up and then went back to pretty much no line now I'm on cycle day 31 my cycles are 36-37 days long. Could I have missed ovulation or could I possibly not be ovulating at all? Frustrating when I'm TTC #2 soonest possible