Ovulation confusion 🤔

This is the first time EVER using an ovulation kit, so tell me what I'm doing wrong.Right after my period ended I took an ovulation test and I could see a faint line. Then the next day it was a tad darker. Then on the third and fourth day, it's like there's nothing there if you didn't look very closely. Well, I got a reminder that today is the start of being fertile( no change in test). I test in the morning.TIA #HELP #Confused