I had the exact same thing happen last cycle after being of the pill for around the same time as you, and having about the same regular cycles.

I kept getting BFNs, after AF was late for a week 1/2 I went for a BT. They also tested all my hormones to check everything was OK. Thanks to the weekend and all, by the time I got the results and then met with the Doc again, AF has arrived, it was exactly 2 weeks late. Turns out the cramps when AF was due, was not AF but ovulation cramps, the blood tests confirmed this too. Certainly explained why I had no BFP, the days before and around the cramps I wasn't well and since I thought I was way past O time didn't bother with any BD.

Still good news, I am ovulating and I can possibly tell when with out the charting etc.