Opk question

Lauren • 30. Partner 34. I work as a domestic abuse support worker in a women's refuge and my partner is an independent haulage contractor for CEMEX. We have 2 children. William 9 & Georgia 1.
How negative should an opk be when you're not building up to ovulation. And by how negative I mean, does a pink test line always show or when you're not building up to ovulation is it meant to be just the control line?