Have I ovulated?

I had really intense cramping on my left side low down near where I would imagine my ovaries are on Thursday so thought this may be ovulation, but looking at my opks it doesn't look like I've ovulated? My lines got darker but never as dark as the control line? I've also been using the Clearblue digital opk and have had high readings since Thursday - no peak reading yet but my lines have been getting lighter the last few days so is it possible I've already ovulated? Please help!! Been ttc 4 months now x