The bi-variate correlations between the probability of conception on a given calendar-day and IPT pain tolerance for naturally cycling pair-bonded and single women and women using contraceptives.

<p>Probability of conception was calculated using the Wilcox findings which provide a precise estimate of the risk of pregnancy relative to intercourse on a given cycle day (counting from onset of previous menses; <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0091993#pone.0091993-Wilcox1" target="_blank">[77]</a>).