Weird ovulation

This is kinda silly and lame, but I'm curious if it's happened to anyone else on here. I use Clearblue digital opk. Normally I'll have 3-5 days of the blinking smiley, meaning high fertility, and then finally get my solid smiley, meaning peak fertility. This month I had two days of the blank circle, and then immediately got the solid smiley. No high fertility. That's just really unusual for me. So I'm curious, has anyone else who uses these opk's had this before?