Invalid opk?

Gabrielle • Mama, published model, tattoo & animal lover

So far I’ve had five positive opks. I’m pretty sure with this brand it says to disregard after five minutes. In the five minutes I thought it was negative. Another minute or two it got dark. Should I ignore this or take it as a positive? I started my first positive on cycle day 27. I have irregular periods so I keep taking these until it’s neg lol