Ladies’ I need some help with the OPK, Please.

I’m new to the OPK, this app says I’m ovulating the 28 of this month, I took an ovulation test right now and it was negative, I thought the ovulation test should have the smiley face since I’m close to my ovulation day or does it supposed to happen right on your ovulation day¿¿ plz sooo confused me and my hubby have been trying for 6 months.... but nothing’s working¡ I been using the pre-seed, the prenatal vitamins, the conceive plus ..... I’m really wishing for the baby dust to come soon 😞 .....

Baby dust to all the ladies out there, Good Luck 🍀👍