OPK Help

Alex • Married to my best friend and the love of my life -- my Airman. Michigan born and raised. TTC #1!
So I bought some of the digital ovulation tests to try this month. I started taking them two days ago and each one had the blank circle, so they were negative. This morning I noticed I was having a lot of the stretchy, egg white cm and I took a third test and it was the plain smiley, which means peak fertility. 
I'm just surprised since I had two negatives beforehand. All were used with first morning urine too. Is that possible? According to glow I'm supposed to ovulate later this week, like I did last month.