Ovulation false positive?

My opk flashes a smiley during my 4 most fertile days. I got a smiley on cd 12.  This is very early for me since I have a 34 day cycle. It's been flashing for 5 days so I bought a new pack. The new pack shows no fertility. Is the first one bad? I buy the digital ones because I can never figure out if I'm ovulating with the other. Anyone had good luck with the clear blue? What other brands work? I'm starting to wonder if it's my body.