been tracking my cm lately and according to glow my fertile period was 3 weeks ago and we bd ... but 7 days ago i noticed by cm that it was the perfect time to bd ... and so we did. aunt flow supposed to be tomorrow && no pre af syptoms ... i tested yesterday BFN... could i have actually been fertile a week before af? advice from women who have concieved on this method or who have been trying to concieve on this method .. ... i guess i just need insight to this method.