Help! Ovulation testing!

Amy • Married 5 years ❤️; Fur Momma 🐾; PCOS; One Miscarriage 💙; 🌈 Hadlee 🎀

So I’ve been using the First Response ovulation tests and they have all been very clearly negative. Today I used one after four hours of holding urine. I got a negative, as shown below, but THEN for the heck of it I got a blinking smiley face with the Clear Blue Advanced!

Which one is more accurate?! What could this mean?!