Day 4 high fertility???

Sarah • 41, been ttc 8 months. Just started additional blood tests to check everything OK with me, husband has low motility sample and just started taking vitamins to help.
Hi, wondered if anyone can shed some light ; my ovulation kit is reading 4th day of 'flashing' high fertility. I'm anticipating it turning to a static smiley face meaning peak fertility but beginning to wonder if the test has missed it? Can you have 4 days high??