11 days straight of "high" fertility (blinking smiley)

Ashley • Age 35 * Married since 2014 * TTC #1 for 2 years! BFP 11/20/18 ❤️
Is this possible? Is my fertility tester broken? I'm so confused! I'm 8 days out from my period and still testing high (blinking smiley) and started testing on day 4 of my cycle (that when I should start because I'm irregular) and by day 5 I was showing high. Is something wrong?