How to judge ovulation test paper (the correct way to use ovulation test paper) Ovulation is one of the most critical aspects of a woman\’s fertility process. For women trying to conceive a baby, it can be helpful to know exactly when they ovulate. For women, ovulation test strips are a common tool to determine the time of ovulation. So, this article will start from the usage method, usage time, usage frequency and usage ring of ovulation test strips.