Opk confusion

Im currently CD30 and got a BFN. AF due on Friday. cycle seems to be 34 days long. My clearblue digital opk confused me this month as it was my first round of Femara. CD13 I got a "high" fertility (flashing smiley) CD14 I got "peak" (solid smiley) CD15 was back to "low" (blank smiley) but I didn't feel like I had ovulated. CD16 I tested again and got another Peak and I tested again on CD17 as it was so confusing and again I got a Peak once again. CD18 was low, and I gave up testing after that because it was just stupid. Me and hubby DTD on CD13-14 and again CD16-17 - anyone think my BFN could be a false negative?