When It's Time For Sex, She Knows

Women are more likely to have sex during the most fertile six days of their menstrual cycle, even if they don't want to get pregnant, according to a study published in the journal Human Reproduction. Scientists studying sexually active women who had been sterilized or were using an IUD found that intercourse was 24% more frequent during what would have been the fertile part of their cycle — although these women were clearly not looking to procreate. So why the urge? Researchers speculate that a woman's libido may rise during ovulation or that her sexual attractiveness to partners may increase. It could also be that intercourse accelerates ovulation. There aren't any definitive answers yet, but women who have unprotected sex and do not want to get pregnant should know that nature appears to be subtly working against them.